Infrastructure Router Security Technical Implementation Guide Juniper

U_Network_Infrastructure_Router_Juniper_V8R20_Manual-xccdf.xml

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V8R20 2016-07-07      
Update existing CKLs to this version of the STIG
Infrastructure Router Security Technical Implementation Guide – Juniper
Vuln Rule Version CCI Severity Title Description
SV-15475r3_rule NET1020 LOW The network device must log all access control lists (ACL) deny statements. Auditing and logging are key components of any security architecture. It is essential for security personnel to know what is being done, attempted to be done, and by whom in order to compile an accurate risk assessment. Auditing the actions on network devices provides a means to recreate an attack, or identify a configuration mistake on the device.Information Assurance OfficerECAT-1, ECAT-2, ECSC-1
SV-3008r1_rule NET1800 MEDIUM The IAO will ensure IPSec VPNs are established as tunnel type VPNs when transporting management traffic across an ip backbone network. Using dedicated paths, the OOBM backbone connects the OOBM gateway routers located at the premise of the managed networks and at the NOC. Dedicated links can be deployed using provisioned circuits (ATM, Frame Relay, SONET, T-carrier, and others or VPN technologies such as subscribing to MPLS Layer 2 and Layer 3 VPN services) or implementing a secured path with gateway-to-gateway IPsec tunnel. The tunnel mode ensures that the management traffic will be logically separated from any other traffic traversing the same path.Information Assurance Officer
SV-3012r4_rule NET0230 HIGH Network devices must be password protected. Network access control mechanisms interoperate to prevent unauthorized access and to enforce the organization's security policy. Access to the network must be categorized as administrator, user, or guest so the appropriate authorization can be assigned to the user requesting access to the network or a network device. Authorization requires an individual account identifier that has been approved, assigned, and configured on an authentication server. Authentication of user identities is accomplished through the use of passwords, tokens, biometrics, or in the case of multi-factor authentication, some combination thereof. Lack of authentication enables anyone to gain access to the network or possibly a network device providing opportunity for intruders to compromise resources within the network infrastructure.Information Assurance Officer
SV-3013r4_rule NET0340 MEDIUM Network devices must display the DoD-approved logon banner warning. All network devices must present a DoD-approved warning banner prior to a system administrator logging on. The banner should warn any unauthorized user not to proceed. It also should provide clear and unequivocal notice to both authorized and unauthorized personnel that access to the device is subject to monitoring to detect unauthorized usage. Failure to display the required logon warning banner prior to logon attempts will limit DoD's ability to prosecute unauthorized access and also presents the potential to give rise to criminal and civil liability for systems administrators and information systems managers. In addition, DISA's ability to monitor the device's usage is limited unless a proper warning banner is displayed. DoD CIO has issued new, mandatory policy standardizing the wording of "notice and consent" banners and matching user agreements for all Secret and below DoD information systems, including stand-alone systems by releasing DoD CIO Memo, "Policy on Use of Department of Defense (DoD) Information Systems Standard Consent Banner and User Agreement", dated 9 May 2008. The banner is mandatory and deviations are not permitted except as authorized in writing by the Deputy Assistant Secretary of Defense for Information and Identity Assurance. Implementation of this banner verbiage is further directed to all DoD components for all DoD assets via USCYBERCOM CTO 08-008A.Information Assurance Officer
SV-15454r2_rule NET1639 MEDIUM The network element must timeout management connections for administrative access after 10 minutes or less of inactivity. Setting the timeout of the session to 10 minutes or less increases the level of protection afforded critical network components.Information Assurance Officer
SV-15331r2_rule NET0820 LOW The network element must have DNS servers defined if it is configured as a client resolver. The susceptibility of IP addresses to spoofing translates to DNS host name and IP address mapping vulnerabilities. For example, suppose a source host wishes to establish a connection with a destination host and queries a DNS server for the IP address of the destination host name. If the response to this query is the IP address of a host operated by an attacker, the source host will establish a connection with the attackers host, rather than the intended target. The user on the source host might then provide logon, authentication, and other sensitive data.Information Assurance Officer
SV-15333r2_rule NET0890 MEDIUM The network element must only allow write and poll SNMP access by authorized internal IP addresses. Detailed information about the network is sent across the network via SNMP. If this information is discovered by attackers it could be used to trace the network, show the networks topology, and possibly gain access to network devices.Information Assurance Officer
SV-15291r2_rule NET0400 MEDIUM The network element must authenticate all IGP peers. A rogue router could send a fictitious routing update to convince a site’s premise router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information of the site’s network, or merely used to disrupt the network’s ability to effectively communicate with other networks.Information Assurance Officer
SV-3043r4_rule NET1675 MEDIUM The network device must use different SNMP community names or groups for various levels of read and write access. Numerous vulnerabilities exist with SNMP; therefore, without unique SNMP community names, the risk of compromise is dramatically increased. This is especially true with vendors default community names which are widely known by hackers and other networking experts. If a hacker gains access to these devices and can easily guess the name, this could result in denial of service, interception of sensitive information, or other destructive actions.Information Assurance Officer
SV-3056r7_rule NET0460 HIGH Group accounts must not be configured for use on the network device. Group accounts configured for use on a network device do not allow for accountability or repudiation of individuals using the shared account. If group accounts are not changed when someone leaves the group, that person could possibly gain control of the network device. Having group accounts does not allow for proper auditing of who is accessing or changing the network.Information Assurance Officer
SV-15472r3_rule NET0465 MEDIUM Authorized accounts must be assigned the least privilege level necessary to perform assigned duties. By not restricting authorized accounts to their proper privilege level, access to restricted functions may be allowed before authorized personell are trained or experienced enough to use those functions. Network disruptions or outages may occur due to mistakes made by inexperienced persons using accounts with greater privileges than necessary.Information Assurance OfficerECSC-1
SV-3058r5_rule NET0470 MEDIUM Unauthorized accounts must not be configured for access to the network device. A malicious user attempting to gain access to the network device may compromise an account that may be unauthorized for use. The unauthorized account may be a temporary or inactive account that is no longer needed to access the device. Denial of Service, interception of sensitive information, or other destructive actions could potentially take place if an unauthorized account is configured to access the network device.Information Assurance Officer
SV-41451r2_rule NET0600 HIGH The network element must be configured to ensure passwords are not viewable when displaying configuration information. Many attacks information systems and network elements are launched from within the network. Hence, it is imperative that all passwords are encrypted so they cannot be intercepted by viewing the console or printout of the configuration. Information Assurance OfficerECSC-1
SV-15452r3_rule NET1638 MEDIUM Management connections to a network device must be established using secure protocols with FIPS 140-2 validated cryptographic modules. Administration and management connections performed across a network are inherently dangerous because anyone with a packet sniffer and access to the right LAN segment can acquire the network device account and password information. With this intercepted information they could gain access to the router and cause denial of service attacks, intercept sensitive information, or perform other destructive actions.Information Assurance OfficerDCNR-1, ECSC-1
SV-15456r2_rule NET1640 LOW The network element must log all attempts to establish a management connection for administrative access. Audit logs are necessary to provide a trail of evidence in case the network is compromised. Without an audit trail that provides a when, where, who and how set of information, repeat offenders could continue attacks against the network indefinitely. With this information, the network administrator can devise ways to block the attack and possibly identify and prosecute the attacker.Information Assurance Officer
SV-15306r2_rule NET0730 LOW The network element must have the Finger service disabled. The finger service supports the UNIX finger protocol, which is used for querying a host about the users that are logged on. This service is not necessary for generic users. If an attacker were to find out who is using the network, they may use social engineering practices to try to elicit classified DoD information. Information Assurance Officer
SV-15317r2_rule NET0770 MEDIUM The router must have IP source routing disabled. Source routing is a feature of IP, whereby individual packets can specify routes. This feature is used in several different network attacks by bypassing perimeter and internal defense mechanisms.Information Assurance Officer
SV-41468r1_rule NET0740 MEDIUM The network element must have HTTP service for administrative access disabled. The additional services that the router is enabled for increases the risk for an attack since the router will listen for these services. In addition, these services provide an unsecured method for an attacker to gain access to the router. Most recent software versions support remote configuration and monitoring using the World Wide Web's HTTP protocol. In general, HTTP access is equivalent to interactive access to the router. The authentication protocol used for HTTP is equivalent to sending a clear-text password across the network, and, unfortunately, there is no effective provision in HTTP for challenge-based or one-time passwords. This makes HTTP a relatively risky choice for use across the public Internet. Any additional services that are enabled increase the risk for an attack since the router will listen for these services.Information Assurance Officer
SV-3143r4_rule NET0240 HIGH Network devices must not have any default manufacturer passwords. Network devices not protected with strong password schemes provide the opportunity for anyone to crack the password thus gaining access to the device and causing network outage or denial of service. Many default vendor passwords are well-known; hence, not removing them prior to deploying the network devices into production provides an opportunity for a malicious user to gain unauthorized access to the device.Information Assurance Officer
SV-15303r2_rule NET0700 MEDIUM The network element must be running a current and supported operating system with all IAVMs addressed. Network devices that are not running the latest tested and approved versions of software are vulnerable to network attacks. Running the most current, approved version of system and device software helps the site maintain a stable base of security fixes and patches, as well as enhancements to IP security. Viruses, denial of service attacks, system weaknesses, back doors and other potentially harmful situations could render a system vulnerable, allowing unauthorized access to DoD assets.Information Assurance Officer
SV-28748r3_rule NET1636 HIGH The network device must require authentication prior to establishing a management connection for administrative access. Network devices with no password for administrative access via a management connection provide the opportunity for anyone with network access to the device to make configuration changes enabling them to disrupt network operations resulting in a network outage.Information Assurance OfficerECSC-1
SV-3196r4_rule NET1660 HIGH The network device must use SNMP Version 3 Security Model with FIPS 140-2 validated cryptography for any SNMP agent configured on the device. SNMP Versions 1 and 2 are not considered secure. Without the strong authentication and privacy that is provided by the SNMP Version 3 User-based Security Model (USM), an unauthorized user can gain access to network management information used to launch an attack against the network.Information Assurance Officer
SV-3210r4_rule NET1665 HIGH The network device must not use the default or well-known SNMP community strings public and private. Network devices may be distributed by the vendor pre-configured with an SNMP agent using the well-known SNMP community strings public for read only and private for read and write authorization. An attacker can obtain information about a network device using the read community string "public". In addition, an attacker can change a system configuration using the write community string "private".Information Assurance Officer
SV-30085r4_rule NET0440 MEDIUM In the event the authentication server is down or unavailable, there must only be one local account of last resort created for emergency use. Authentication for administrative access to the device is required at all times. A single account of last resort can be created on the device's local database for use in an emergency such as when the authentication server is down or connectivity between the device and the authentication server is not operable. The console or account of last resort logon credentials must be stored in a sealed envelope and kept in a safe.
SV-15445r2_rule NET1624 MEDIUM The network element must time out access to the console port after 10 minutes or less of inactivity. Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition quickly terminating an idle session will also free up resources committed by the managed network element. Setting the timeout of the session to 10 minutes or less increases the level of protection afforded critical network components.Information Assurance Officer
SV-30087r3_rule NET0894 MEDIUM The network device must only allow SNMP read-only access. Enabling write access to the router via SNMP provides a mechanism that can be exploited by an attacker to set configuration variables that can disrupt network operations.Information Assurance OfficerECSC-1
SV-28747r3_rule NET1623 HIGH The network device must require authentication for console access. Network devices with no password for administrative access via the console provide the opportunity for anyone with physical access to the device to make configuration changes enabling them to disrupt network operations resulting in a network outage.Information Assurance OfficerIAIA-1, IAIA-2
SV-4583r1_rule NET0580 LOW The router administrator will ensure a password is required to gain access to the router's diagnostics port. If unauthorized users gain access to the routers diagnostic port, it is possible to disrupt service.Information Assurance Officer
SV-15477r2_rule NET1021 LOW The network element must log all messages except debugging and send all log data to a syslog server. Logging is a critical part of router security. Maintaining an audit trail of system activity logs (syslog) can help identify configuration errors, understand past intrusions, troubleshoot service disruptions, and react to probes and scans of the network. Syslog levels 0-6 are the levels required to collect the necessary information to help in the recovery process.Information Assurance Officer
SV-15450r2_rule NET1637 MEDIUM The network element must only allow management connections for administrative access from hosts residing in to the management network. Remote administration is inherently dangerous because anyone with a sniffer and access to the right LAN segment, could acquire the device account and password information. With this intercepted information they could gain access to the infrastructure and cause denial of service attacks, intercept sensitive information, or perform other destructive actions.Information Assurance Officer
SV-28744r2_rule NET1645 MEDIUM The network element must be configured to timeout after 60 seconds or less for incomplete or broken SSH sessions. An attacker may attempt to connect to the device using SSH by guessing the authentication method, encryption algorithm, and keys. Limiting the amount of time allowed for authenticating and negotiating the SSH session reduces the window of opportunity for the malicious user attempting to make a connection to the network element.Information Assurance Officer
SV-28745r2_rule NET1646 MEDIUM The network element must be configured for a maximum number of unsuccessful SSH login attempts set at 3 before resetting the interface. An attacker may attempt to connect to the device using SSH by guessing the authentication method and authentication key or shared secret. Setting the authentication retry to 3 or less strengthens against a Brute Force attack.Information Assurance Officer
SV-15437r4_rule NET0965 MEDIUM The network device must drop half-open TCP connections through filtering thresholds or timeout periods. A TCP connection consists of a three-way handshake message sequence. A connection request is transmitted by the originator, an acknowledgement is returned from the receiver, and then an acceptance of that acknowledgement is sent by the originator. An attacker’s goal in this scenario is to cause a denial of service to the network or device by initiating a high volume of TCP packets, then never sending an acknowledgement, leaving connections in a half-opened state. Without the device having a connection or time threshold for these half-opened sessions, the device risks being a victim of a denial of service attack. Setting a TCP timeout threshold will instruct the device to shut down any incomplete connections. Services such as SSH, BGP, SNMP, LDP, etc. are some services that may be prone to these types of denial of service attacks. If the router does not have any BGP connections with BGP neighbors across WAN links, values could be set to even tighter constraints.Information Assurance OfficerECSC-1
SV-15447r2_rule NET1629 LOW The network element’s auxiliary port must be disabled unless it is connected to a secured modem providing encryption and authentication. The use of POTS lines to modems connecting to network devices provides clear text of authentication traffic over commercial circuits that could be captured and used to compromise the network. Additional war dial attacks on the device could degrade the device and the production network. Secured modem devices must be able to authenticate users and must negotiate a key exchange before full encryption takes place. The modem will provide full encryption capability (Triple DES) or stronger. The technician who manages these devices will be authenticated using a key fob and granted access to the appropriate maintenance port, thus the technician will gain access to the managed device (router, switch, etc.). The token provides a method of strong (two-factor) user authentication. The token works in conjunction with a server to generate one-time user passwords that will change values at second intervals. The user must know a personal identification number (PIN) and possess the token to be allowed access to the device. Information Assurance Officer
SV-15301r3_rule NET0422 LOW Network devices must be configured with rotating keys used for authenticating IGP peers that have a duration exceeding 180 days. If the keys used for routing protocol authentication are guessed, the malicious user could create havoc within the network by advertising incorrect routes and redirecting traffic. Changing the keys frequently reduces the risk of them eventually being guessed. When configuring authentication for routing protocols that provide key chains, configure two rotating keys with overlapping expiration dates, both with 180-day expirations.Information Assurance Officer
SV-15312r1_rule NET0742 MEDIUM The router administrator will ensure FTP server is disabled. The additional services enabled on a router increases the risk for an attack since the router will listen for these services. In addition, these services provide an unsecured method for an attacker to gain access to the router.Information Assurance Officer
SV-15315r2_rule NET0744 MEDIUM The network element must have all BSDr commands disabled. Berkeley Software Distribution (BSD) “r” commands allow users to execute commands on remote systems using a variety of protocols. The BSD "r" commands (e.g., rsh, rlogin, rcp, rdump, rrestore, and rdist) are designed to provide convenient remote access without passwords to services such as remote command execution (rsh), remote login (rlogin), and remote file copy (rcp and rdist). The difficulty with these commands is that they use address-based authentication. An attacker who convinces a server that he is coming from a "trusted" machine can essentially get complete and unrestricted access to a system. The attacker can convince the server by impersonating a trusted machine and using IP address, by confusing DNS so that DNS thinks that the attacker's IP address maps to a trusted machine's name, or by any of a number of other methodsInformation Assurance Officer
SV-15322r1_rule NET0802 MEDIUM The router administrator will ensure ICMPv6 unreachable notifications, and redirects are disabled on all external interfaces of the premise router. The Internet Control Message Protocol version 6 (ICMPv6) supports IPv6 traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMPv6 messages under a wide variety of conditions. ICMPv6 messages are commonly used by attackers for network mapping and diagnosis: Host unreachable, and Redirect.Information Assurance Officer
SV-16090r1_rule NET0813 MEDIUM The IAO will ensure all NTP-enabled devices authenticate received NTP messages. Since NTP is used to ensure accurate log file timestamp information, NTP could pose a security risk if a malicious user were able to falsify NTP information. To launch an attack on the NTP infrastructure, a hacker could inject time that would be accepted by NTP clients by spoofing the IP address of a valid NTP server. To mitigate this risk, the time messages must be authenticated by the client before accepting them as a time source. Two NTP-enabled devices can communicate in either client-server mode or peer-to-peer mode (aka “symmetric mode”). The peering mode is configured manually on the device and indicated in the outgoing NTP packets. The fundamental difference is the synchronization behavior: an NTP server can synchronize to a peer with better stratum, whereas it will never synchronize to its client regardless of the client’s stratum. From a protocol perspective, NTP clients are no different from the NTP servers. The NTP client can synchronize to multiple NTP servers, select the best server and synchronize with it, or synchronize to the averaged value returned by the servers. A hierarchical model can be used to improve scalability. With this implementation, an NTP client can also become an NTP server providing time to downstream clients at a higher stratum level and of decreasing accuracy than that of its upstream server. To increase availability, NTP peering can be used between NTP servers. In the event the device looses connectivity to it upstream NTP server, it will be able to choose time from one of its peers. The NTP authentication model is opposite of the typical client-server authentication model. NTP authentication enables an NTP client or peer to authenticate time received from their servers and peers. It’s not used to authenticate NTP clients because NTP servers don’t care about the authenticity of their clients, as they never accept any time from them. Information Assurance Officer
SV-16092r2_rule NET0897 LOW The router must use its loopback or OOB management interface address as the source address when originating TACACS+ or RADIUS traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. TACACS+, RADIUS messages sent to management servers should use the loopback address as the source address. Information Assurance Officer
SV-15341r2_rule NET0898 LOW The router must use its loopback or OOB management interface address as the source address when originating syslog traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. Syslog messages sent to management servers should use the loopback address as the source address.Information Assurance Officer
SV-15344r2_rule NET0899 LOW The router must use its loopback or OOB management interface address as the source address when originating NTP traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. NTP messages sent to management servers should use the loopback address as the source address. Information Assurance Officer
SV-15347r2_rule NET0900 LOW The router must use its loopback or OOB management interface address as the source address when originating SNMP traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. SNMP messages sent to management servers should use the loopback address as the source address. Information Assurance Officer
SV-15350r2_rule NET0901 LOW The router must use its loopback or OOB management interface address as the source address when originating NetFlow traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. Netflow messages sent to management servers should use the loopback address as the source address. Information Assurance Officer
SV-15353r3_rule NET0902 LOW The network device must use its loopback or OOB management interface address as the source address when originating TFTP or FTP traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of network devices. It is easier to construct appropriate ingress filters for management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. TFTP and FTP messages sent to management servers should use the loopback address as the source address.Information Assurance OfficerECSC-1
SV-15360r2_rule NET0903 LOW The router must use its loopback interface address as the source address for all iBGP peering sessions. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability. It is easier to construct appropriate filters for control plane traffic. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses.Information Assurance Officer
SV-15397r2_rule NET-IPV6-025 MEDIUM The network device must be configured to ensure IPv6 Site Local Unicast addresses are not defined in the enclave, (FEC0::/10). Note that this consist of all addresses that begin with FEC, FED, FEE and FEF. As currently defined, site local addresses are ambiguous and can be present in multiple sites. The address itself does not contain any indication of the site to which it belongs. The use of site-local addresses has the potential to adversely affect network security through leaks, ambiguity and potential misrouting, as documented in section 2 of RFC3879. RFC3879 formally deprecates the IPv6 site-local unicast prefix defined in RFC3513, i.e., 1111111011 binary or FEC0::/10.Information Assurance OfficerECSC-1
SV-15430r1_rule NET-IPV6-034 MEDIUM The network element must be configured from accepting any outbound IP packet that contains an illegitimate address in the source address field via egress ACL or by enabling Unicast Reverse Path Forwarding in an IPv6 enclave. Unicast Reverse Path Forwarding (uRPF) provides a mechanism for IP address spoof protection. When uRPF is enabled on an interface, the router examines all packets received as input on that interface to make sure that the source address and source interface appear in the routing table and match the interface on which the packet was received. If the packet was received from one of the best reverse path routes, the packet is forwarded as normal. If there is no reverse path route on the same interface from which the packet was received, it might mean that the source address was modified. If Unicast RPF does not find a reverse path for the packet, the packet is dropped. If internal nodes automatically configure an address based on a prefix from a bogus Router Advertisement a dangerous situation may exist. An internal host may contact an internal server which responds with a packet that could be routed outside of the network via default routing (because the routers do not recognize the destination address as an internal address). To prevent this, filtering should be applied to network interfaces between internal host LANs and internal server LANs to insure that source addresses have valid prefixes. Information Assurance Officer
SV-15461r2_rule NET1647 MEDIUM The network element must not use SSH Version 1 for administrative access. SSH Version 1 is a protocol that has never been defined in a standard. Since SSH-1 has inherent design flaws which make it vulnerable to, e.g., man-in-the-middle attacks, it is now generally considered obsolete and should be avoided by explicitly disabling fallback to SSH-1. Information Assurance Officer
SV-16067r2_rule NET-TUNL-017 MEDIUM ISATAP tunnels must terminate at an interior router. ISATAP is an automatic tunnel mechanism that does not provide authentication such as IPSec. As a result of this limitation, ISATAP is thought of as a tool that is used inside the enclave among trusted hosts, which would limit it to internal attacks. ISATAP is a service versus a product, and is readily available to most users. If a user knows the ISATAP router IP address, they can essentially get onto the IPv6 intranet. To control the vulnerability of this tunnel mechanism, it is critical to control the use of protocol 41 and use IPv4 filters to control what IPv4 nodes can send protocol 41 packets to an ISATAP router interface. Although the ISATAP tunneling mechanism is similar to other automatic tunneling mechanisms, such as IPv6 6to4 tunneling, ISATAP is designed for transporting IPv6 packets between sites within an enclave, not between enclaves.Information Assurance OfficerECSC-1
SV-16259r4_rule NET0433 MEDIUM Network devices must use two or more authentication servers for the purpose of granting administrative access. The use of Authentication, Authorization, and Accounting (AAA) affords the best methods for controlling user access, authorization levels, and activity logging. By enabling AAA on the routers in conjunction with an authentication server such as TACACS+ or RADIUS, the administrators can easily add or remove user accounts, add or remove command authorizations, and maintain a log of user activity. The use of an authentication server provides the capability to assign router administrators to tiered groups that contain their privilege level that is used for authorization of specific commands. For example, user mode would be authorized for all authenticated administrators while configuration or edit mode should only be granted to those administrators that are permitted to implement router configuration changes.Information Assurance Officer
SV-16261r5_rule NET0441 HIGH The emergency administration account must be set to an appropriate authorization level to perform necessary administrative functions when the authentication server is not online. The emergency administration account is to be configured as a local account on the network devices. It is to be used only when the authentication server is offline or not reachable via the network. The emergency account must be set to an appropriate authorization level to perform necessary administrative functions during this time.Information Assurance Officer
SV-18945r2_rule NET1807 MEDIUM IPSec tunnels used to transit management traffic must be restricted to only the authorized management packets based on destination and source IP address. The Out-of-Band Management (OOBM) network is an IP network used exclusively for the transport of OAM&P data from the network being managed to the OSS components located at the NOC. Its design provides connectivity to each managed network device enabling network management traffic to flow between the managed NEs and the NOC. This allows the use of paths separate from those used by the network being managed. Traffic from the managed network to the management network and vice-versa must be secured via IPSec encapsulation.Information Assurance Officer
SV-19063r1_rule NET1808 MEDIUM Gateway configuration at the remote VPN end-point is a not a mirror of the local gateway The IPSec tunnel end points may be configured on the OOBM gateway routers connecting the managed network and the NOC. They may also be configured on a firewall or VPN concentrator located behind the gateway router. In either case, the crypto access-list used to identify the traffic to be protected must be a mirror (both IP source and destination address) of the crypto access list configured at the remote VPN peer.System AdministratorInformation Assurance Officer
SV-19298r1_rule NET0985 MEDIUM IGP instances configured on the OOBM gateway router do not peer only with their appropriate routing domain If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries. Since the managed network and the management network are separate routing domains, separate IGP routing instances must be configured on the router—one for the managed network and one for the OOBM network. System Administrator
SV-19300r1_rule NET0986 MEDIUM The routes from the two IGP domains are redistributed to each other. If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries. Since the managed network and the management network are separate routing domains, separate IGP routing instances must be configured on the router—one for the managed network and one for the OOBM network. In addition, the routes from the two domains must not be redistributed to each other. System AdministratorInformation Assurance Officer
SV-19302r1_rule NET0987 MEDIUM Traffic from the managed network is able to access the OOBM gateway router If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries. It is imperative that hosts from the managed network are not able to access the OOBM gateway rouiter.System AdministratorInformation Assurance Officer
SV-19304r1_rule NET0988 MEDIUM Traffic from the managed network will leak into the management network via the gateway router interface connected to the OOBM backbone. If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries such as using interface ACLs or filters at the boundaries between the two networks. System AdministratorInformation Assurance Officer
SV-19306r1_rule NET0989 MEDIUM Management network traffic is leaking into the managed network. If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries. To provide separation, access control lists or filters must be configured to block any traffic from the management network destined for the managed network’s production address spaces.System AdministratorInformation Assurance Officer
SV-20206r2_rule NET0991 MEDIUM The network element’s OOBM interface must be configured with an OOBM network address. The OOBM access switch will connect to the management interface of the managed network elements. The management interface of the managed network element will be directly connected to the OOBM network. An OOBM interface does not forward transit traffic; thereby, providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures that congestion or failures in the managed network do not affect the management of the device. If the OOBM interface does not have an IP address from the managed network address space, it will not have reachability from the NOC using scalable and normal control plane and forwarding mechanisms.System AdministratorInformation Assurance Officer
SV-20209r1_rule NET0992 MEDIUM The management interface is not configured with both an ingress and egress ACL. The OOBM access switch will connect to the management interface of the managed network elements. The management interface can be a true OOBM interface or a standard interface functioning as the management interface. In either case, the management interface of the managed network element will be directly connected to the OOBM network. An OOBM interface does not forward transit traffic; thereby, providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures that congestion or failures in the managed network do not affect the management of the device. If the device does not have an OOBM port, the interface functioning as the management interface must be configured so that management traffic does not leak into the managed network and that production traffic does not leak into the management network System AdministratorInformation Assurance Officer
SV-19335r2_rule NET0993 LOW The network element’s management interface is not configured as passive for the IGP instance deployed in the managed network. The OOBM access switch will connect to the management interface of the managed network elements. The management interface can be a true OOBM interface or a standard interface functioning as the management interface. In either case, the management interface of the managed network element will be directly connected to the OOBM network. An OOBM interface does not forward transit traffic; thereby, providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures congestion or failures in the managed network do not affect the management of the device. If the device does not have an OOBM port, the interface functioning as the management interface must be configured so management traffic, both data plane and control plane, does not leak into the managed network and production traffic does not leak into the management network. System AdministratorInformation Assurance Officer
SV-19309r1_rule NET1005 MEDIUM An inbound ACL is not configured for the management network sub-interface of the trunk link to block non-management traffic. If the management systems reside within the same layer 2 switching domain as the managed network elements, then separate VLANs will be deployed to provide separation at that level. In this case, the management network still has its own subnet while at the same time it is defined as a unique VLAN. Inter-VLAN routing or the routing of traffic between nodes residing in different subnets requires a router or multi-layer switch (MLS). Access control lists must be used to enforce the boundaries between the management network and the network being managed. All physical and virtual (i.e. MLS SVI) routed interfaces must be configured with ACLs to prevent the leaking of unauthorized traffic from one network to the other. System AdministratorInformation Assurance Officer
SV-19311r1_rule NET1006 MEDIUM Traffic entering the tunnels is not restricted to only the authorized management packets based on destination address. Similar to the OOBM model, when the production network is managed in-band, the management network could also be housed at a NOC that is located locally or remotely at a single or multiple interconnected sites. NOC interconnectivity as well as connectivity between the NOC and the managed networks’ premise routers would be enabled using either provisioned circuits or VPN technologies such as IPSec tunnels or MPLS VPN services. System AdministratorInformation Assurance Officer
SV-19314r1_rule NET1007 LOW Management traffic is not classified and marked at the nearest upstream MLS or router when management traffic must traverse several nodes to reach the management network. When network congestion occurs, all traffic has an equal chance of being dropped. Prioritization of network management traffic must be implemented to ensure that even during periods of severe network congestion, the network can be managed and monitored. Quality of Service (QoS) provisioning categorizes network traffic, prioritizes it according to its relative importance, and provides priority treatment through congestion avoidance techniques. Implementing QoS within the network makes network performance more predictable and bandwidth utilization more effective. Most important, since the same bandwidth is being used to manage the network, it provides some assurance that there will be bandwidth available to troubleshoot outages and restore availability when needed. When management traffic must traverse several nodes to reach the management network, management traffic should be classified and marked at the nearest upstream MLS or router. In addition, all core routers within the managed network must be configured to provide preferred treatment based on the QoS markings. This will ensure that management traffic receives preferred treatment (per-hop behavior) at each forwarding device along the path to the management network. traffic. System AdministratorInformation Assurance Officer
SV-19316r1_rule NET1008 LOW The core router within the managed network has not been configured to provide preferred treatment for management traffic that must traverse several nodes to reach the management network. When network congestion occurs, all traffic has an equal chance of being dropped. Prioritization of network management traffic must be implemented to ensure that even during periods of severe network congestion, the network can be managed and monitored. Quality of Service (QoS) provisioning categorizes network traffic, prioritizes it according to its relative importance, and provides priority treatment through congestion avoidance techniques. Implementing QoS within the network makes network performance more predictable and bandwidth utilization more effective. Most important, since the same bandwidth is being used to manage the network, it provides some assurance that there will be bandwidth available to troubleshoot outages and restore availability when needed. When management traffic must traverse several nodes to reach the management network, management traffic should be classified and marked at the nearest upstream MLS or router. In addition, all core routers within the managed network must be configured to provide preferred treatment based on the QoS markings. This will ensure that management traffic receives preferred treatment (per-hop behavior) at each forwarding device along the path to the management network. traffic. System AdministratorInformation Assurance Officer
SV-20061r2_rule NET-SRVFRM-003 MEDIUM Server VLAN interfaces must be protected by restrictive ACLs using a deny-by-default security posture. Protecting data sitting in a server VLAN is necessary and can be accomplished using access control lists on VLANs provisioned for servers. Without proper access control of traffic entering or leaving the server VLAN, potential threats such as a denial of service, data corruption, or theft could occur, resulting in the inability to complete mission requirements by authorized users.Information Assurance OfficerECSC-1
SV-20504r2_rule NET-TUNL-012 MEDIUM Default routes must not be directed to the tunnel entry point. Routing in the network containing the tunnel entry point must be configured to direct the intended traffic into the tunnel. Depending on the router products used this may be done by creating routes to a tunnel by name, by address, or by interface. If multiple tunnels are defined or IPv6 interfaces, you must be selective with static routes, policy based routing, or even let the interior gateway protocol (IGP) make the decision since a ipv4 or ipv6 address has been configured on the tunnel. The key is the administrator should carefully plan and configure or let the IGP determine what goes into each tunnel.Information Assurance OfficerECSC-1
SV-21168r2_rule NET0966 MEDIUM Control plane protection is not enabled. The Route Processor (RP) is critical to all network operations as it is the component used to build all forwarding paths for the data plane via control plane processes. It is also instrumental with ongoing network management functions that keep the routers and links available for providing network services. Hence, any disruption to the RP or the control and management planes can result in mission critical network outages. In addition to control plane and management plane traffic that is in the router’s receive path, the RP must also handle other traffic that must be punted to the RP—that is, the traffic must be fast or process switched. This is the result of packets that must be fragmented, require an ICMP response (TTL expiration, unreachable, etc.) have IP options, etc. A DoS attack targeting the RP can be perpetrated either inadvertently or maliciously involving high rates of punted traffic resulting in excessive RP CPU and memory utilization. To maintain network stability, the router must be able to securely handle specific control plane and management plane traffic that is destined to it, as well as other punted traffic. Using the ingress filter on forwarding interfaces is a method that has been used in the past to filter both forwarding path and receiving path traffic. However, this method does not scale well as the number of interfaces grows and the size of the ingress filters grow. Control plane policing can be used to increase security of routers and multilayer switches by protecting the RP from unnecessary or malicious traffic. Filtering and rate limiting the traffic flow of control plane packets can be implemented to protect routers against reconnaissance and DoS attacks allowing the control plane to maintain packet forwarding and protocol states despite an attack or heavy load on the router or multilayer switch. System AdministratorInformation Assurance Officer
SV-21170r1_rule NET-MCAST-010 LOW Long Name: The administrator must ensure that multicast routers are configured to establish boundaries for Admin-local or Site-local scope multicast traffic. A scope zone is an instance of a connected region of a given scope. Zones of the same scope cannot overlap while zones of a smaller scope will fit completely within a zone of a larger scope. For example, Admin-local scope is smaller than Site-local scope, so the administratively configured boundary fits within the bounds of a site. According to RFC 4007 IPv6 Scoped Address Architecture (section 5), scope zones are also required to be "convex from a routing perspective"-that is, packets routed within a zone must not pass through any links that are outside of the zone. This requirement forces each zone to be one contiguous island rather than a series of separate islands. As stated in the DoD IPv6 IA Guidance for MO3, "One should be able to identify all interfaces of a zone by drawing a closed loop on their network diagram, engulfing some routers and passing through some routers to include only some of their interfaces." Administrative scoped multicast addresses are locally assigned and are to be used exclusively by the enterprise network or enclave. Hence, administrative scoped multicast traffic must not cross the perimeter of the enclave in either direction. Admin-local scope could be used to contain multicast traffic to a portion of an enclave or within a site. This can make it more difficult for a malicious user to access sensitive traffic if the traffic is restricted to links that the user does not have access to. Admin-local scope is encouraged for any multicast traffic within a network that is intended for network management as well as control plane traffic that must reach beyond link-local destinations.System AdministratorInformation Assurance Officer
SV-41498r1_rule NET0812 LOW The network element must use two or more NTP servers to synchronize time. Without synchronized time, accurately correlating information between devices becomes difficult, if not impossible. If you cannot successfully compare logs between each of your routers, switches, and firewalls, it will be very difficult to determine the exact events that resulted in a network breach incident. NTP provides an efficient and scalable method for network elements to synchronize to an accurate time source.System AdministratorInformation Assurance Officer
SV-36774r4_rule NET0405 MEDIUM A service or feature that calls home to the vendor must be disabled. Call home services or features will routinely send data such as configuration and diagnostic information to the vendor for routine or emergency analysis and troubleshooting. The risk that transmission of sensitive data sent to unauthorized persons could result in data loss or downtime due to an attack.Information Assurance OfficerNetwork Security Officer
SV-40313r1_rule NET-MCAST-001 MEDIUM The administrator must ensure that Protocol Independent Multicast (PIM) is disabled on all interfaces that are not required to support multicast routing. A scope zone is an instance of a connected region of a given scope. Zones of the same scope cannot overlap while zones of a smaller scope will fit completely within a zone of a larger scope. For example, Admin-local scope is smaller than Site-local scope, so the administratively configured boundary fits within the bounds of a site. According to RFC 4007 IPv6 Scoped Address Architecture (section 5), scope zones are also required to be “convex from a routing perspective”—that is, packets routed within a zone must not pass through any links that are outside of the zone. This requirement forces each zone to be one contiguous island rather than a series of separate islands. As stated in the DoD IPv6 IA Guidance for MO3, “One should be able to identify all interfaces of a zone by drawing a closed loop on their network diagram, engulfing some routers and passing through some routers to include only some of their interfaces.” Hence, it is imperative that the network has documented their multicast topology and thereby knows which interfaces are enabled for multicast. Once, this is done, the zones can be scoped as required.System Administrator
SV-40316r1_rule NET-MCAST-002 MEDIUM The administrator must ensure that a PIM neighbor filter is bound to all interfaces that have PIM enabled. Protocol Independent Multicast (PIM) is a routing protocol used to build multicast distribution tress for forwarding multicast traffic across the network infrastructure. PIM traffic must be limited to only known PIM neighbors by configuring and binding a PIM neighbor filter to those interfaces that have PIM enabled.Information Assurance Officer
SV-40327r1_rule NET-MCAST-020 LOW The administrator must ensure that multicast groups used for source specific multicast (SSM) routing are from the specific multicast address space reserved for this purpose. Packet origin is a concern because unauthorized sources could potentially send multicast data to a group, using any source address that is permitted. The unauthorized data could impact the integrity of the nodes receiving the data or could create a DoS condition. A receiver that subscribes to an SSM channel only receives data from the requested source. Since a channel is specific to a source, only that source can transmit on that channel. Hence, the SSM model provides more packet origin protection than ASM. To ensure that the subscriber is joining an authorized or known multicast group and source address pair, it is imperative that the group is from the reserved multicast address space as a first step measure.Information Assurance Officer
SV-40390r1_rule NET-IPV6-059 LOW The administrator must ensure that the maximum hop limit is at least 32. The Neighbor Discovery protocol allows a hop limit value to be advertised by routers in a Router Advertisement message to be used by hosts instead of the standardized default value. If a very small value was configured and advertised to hosts on the LAN segment, communications would fail due to hop limit reaching zero before the packets sent by a host reached its destination.Information Assurance Officer
SV-40455r1_rule NET-IPV6-065 MEDIUM The administrator must ensure the 6-to-4 router is configured to drop any IPv4 packets with protocol 41 received from the internal network. The 6to4 specific filters accomplish the role of endpoint verification and provide assurance that the tunnels are being used properly. This primary guidance assumes that only the designated 6to4 router is allowed to form tunnel packets. If they are being formed inside an enclave and passed to the 6to4 router, they are suspicious and must be dropped. In accordance with DoD IPv6 IA Guidance for MO3 (S5-C7-8), packets as such must be dropped and logged as a security event.Information Assurance Officer
SV-40541r1_rule NET-IPV6-066 LOW The administrator must ensure the 6-to-4 router is configured to drop any outbound IPv6 packets from the internal network with a source address that is not within the 6to4 prefix 2002:V4ADDR::/48 where V4ADDR is the designated IPv4 6to4 address for the enclave. An automatic 6to4 tunnel allows isolated IPv6 domains to be connected over an IPv4 network and allows connections to remote IPv6 networks. The key difference between this deployment and manually configured tunnels is that the routers are not configured in pairs and thus do not require manual configuration because they treat the IPv4 infrastructure as a virtual non-broadcast link, using an IPv4 address embedded in the IPv6 address to find the remote end of the tunnel. In other words, the tunnel destination is determined by the IPv4 address of the external interface of the 6to4 router that is concatenated to the 2002::/16 prefix in the format 2002: V4ADDR::/48. Hence, the imbedded V4ADDR of the 6to4 prefix must belong to the same ipv4 prefix as configured on the external-facing interface of the 6to4 router. Information Assurance Officer
SV-40557r1_rule NET-TUNL-034 MEDIUM The administrator must ensure the that all L2TPv3 sessions are authenticated prior to transporting traffic. L2TPv3 sessions can be used to transport layer-2 protocols across an IP backbone. These protocols were intended for link-local scope only and are therefore less defended and not as well-known. As stated in DoD IPv6 IA Guidance for MO3 (S4-C7-1), the L2TP tunnels can also carry IP packets that are very difficult to filter because of the additional encapsulation. Hence, it is imperative that L2TP sessions are authenticated prior to transporting traffic.Information Assurance Officer
SV-41556r2_rule NET0408 MEDIUM The network element must authenticate all BGP peers within the same or between autonomous systems (AS). As specified in RFC 793, TCP utilizes sequence checking to ensure proper ordering of received packets. RFC 793 also specifies that RST (reset) control flags should be processed immediately, without waiting for out of sequence packets to arrive. RFC 793 also requires that sequence numbers are checked against the window size before accepting data or control flags as valid. A router receiving an RST segment will close the TCP session with the BGP peer that is being spoofed; thereby, purging all routes learned from that BGP neighbor. A RST segment is valid as long as the sequence number is within the window. The TCP reset attack is made possible due to the requirements that Reset flags should be processed immediately and that a TCP endpoint must accept out of order packets that are within the range of a window size. This reduces the number of sequence number guesses the attack must make by a factor equivalent to the active window size. Each sequence number guess made by the attacker can be simply incremented by the receiving connections window size. The BGP peering session can protect itself against such an attack by authenticating each TCP segment. The TCP header options include an MD5 signature in every packet and are checked prior to the acceptance and processing of any TCP packet—including RST flags. One way to create havoc in a network is to advertise bogus routes to a network. A rogue router could send a fictitious routing update to convince a BGP router to send traffic to an incorrect or rogue destination. This diverted traffic could be analyzed to learn confidential information of the site’s network, or merely used to disrupt the network’s ability to effectively communicate with other networks. An autonomous system can advertise incorrect information by sending BGP updates messages to routers in a neighboring AS. A malicious AS can advertise a prefix originated from another AS and claim that it is the originator (prefix hijacking). Neighboring autonomous systems receiving this announcement will believe that the malicious AS is the prefix owner and route packets to it.