Intrusion Detection and Prevention Systems (IDPS) Security Requirements Guide

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack databases may result in the compromise of information. Injection attacks allow an attacker to inject code into a program or query or inject malware onto a computer to execute remote commands that can read or modify a database, or change data on a website. Web applications frequently access databases to store, retrieve, and update information. An attacker can construct inputs that the database will execute. This is most commonly referred to as a code injection attack. This type of attack includes XPath and LDAP injections. IDPS component(s) with the capability to prevent code injections must be included in the IDPS implementation to protect against unauthorized data mining. These components must include rules and anomaly detection algorithms to monitor for atypical database queries or accesses.

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack applications may result in the compromise of information. Injection attacks allow an attacker to inject code into a program or query or inject malware onto a computer to execute remote commands that can read or modify a database, or change data on a website. These attacks include buffer overrun, XML, JavaScript, and HTML injections. IDPS component(s) with the capability to prevent code injections must be included in the IDPS implementation to protect against unauthorized data mining. These components must include rules and anomaly detection algorithms to monitor for atypical database queries or accesses.

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack databases may result in the compromise of information. SQL injection attacks are the most prevalent attacks against web applications and databases. These attacks inject SQL commands that can read, modify, or compromise the meaning of the original SQL query. An attacker can spoof identity; expose, tamper, destroy, or make existing data unavailable; or gain unauthorized privileges on the database server. IDPS component(s) with the capability to prevent SQL code injections must be included in the IDPS implementation to protect against unauthorized data mining. These components must include rules and anomaly detection algorithms to monitor for SQL injection attacks.

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack databases may result in the compromise of information. Injection attacks allow an attacker to inject code into a program or query or inject malware onto a computer to execute remote commands that can read or modify a database, or change data on a website. Web applications frequently access databases to store, retrieve, and update information. An attacker can construct inputs that the database will execute. This is most commonly referred to as a code injection attack. This type of attack includes XPath and LDAP injections. IDPS component(s) with anomaly detection must be included in the IDPS implementation to protect against unauthorized data mining. These components must include rules and anomaly detection algorithms to monitor for atypical database queries or accesses.

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack applications may result in the compromise of information. Injection attacks allow an attacker to inject code into a program or query or inject malware onto a computer to execute remote commands that can read or modify a database, or change data on a website. These attacks include buffer overrun, XML, JavaScript, and HTML injections. IDPS component(s) with anomaly detection must be included in the IDPS implementation. These components must include rules and anomaly detection algorithms to monitor for atypical application behavior, commands, and accesses.

Data mining is the analysis of large quantities of data to discover patterns and is used in intelligence gathering. Failure to detect attacks that use unauthorized data mining techniques to attack databases may result in the compromise of information. SQL injection attacks are the most prevalent attacks against web applications and databases. These attacks inject SQL commands that can read, modify, or compromise the meaning of the original SQL query. An attacker can spoof identity; expose, tamper, destroy, or make existing data unavailable; or gain unauthorized privileges on the database server. IDPS component(s) with anomaly detection must be included in the IDPS implementation to monitor for and detect unauthorized data mining. These components must include rules and anomaly detection algorithms to monitor for SQL injection attacks.

The flow of all communications traffic must be monitored and controlled so it does not introduce any unacceptable risk to the network infrastructure or data. Restricting the flow of communications traffic, also known as Information flow control, regulates where information is allowed to travel as opposed to who is allowed to access the information and without explicit regard to subsequent accesses to that information. The IDPS will include policy filters, rules, signatures, and behavior analysis algorithms that inspects and restricts traffic based on the characteristics of the information and/or the information path as it crosses internal network boundaries. The IDPS monitors for harmful or suspicious information flows and restricts or blocks this traffic based on attribute- and content-based inspection of the source, destination, headers, and/or content of the communications traffic.

The flow of all communications traffic must be monitored and controlled so it does not introduce any unacceptable risk to the network infrastructure or data. Restricting the flow of communications traffic, also known as Information flow control, regulates where information is allowed to travel as opposed to who is allowed to access the information and without explicit regard to subsequent accesses to that information. The IDPS will include policy filters, rules, signatures, and behavior analysis algorithms that inspects and restricts traffic based on the characteristics of the information and/or the information path as it crosses external/perimeter boundaries. The IDPS monitors for harmful or suspect information flows and restricts or blocks this traffic based on attribute- and content-based inspection of the source, destination, headers, and/or content of the communications traffic.

Information flow policies regarding dynamic information flow control include, for example, allowing or disallowing information flows based on changes to the PPSM CAL, vulnerability assessments, or mission conditions. Changing conditions include changes in the threat environment and detection of potentially harmful or adverse events. Changes to the IDPS must take effect when made by an authorized administrator and the new configuration is put in place or committed. With some devices, the changes take effect as the configuration is changed, while with others, the new configuration must be submitted to the device. In any case, the behavior of the IDPS must immediately be affected to reflect the configuration change. An IDPS can terminate an information flow if it detects a potentially harmful or adverse event in that specific data flow. This action must take place immediately when triggered.

Information flow policies may require changes in order to meet changing mission needs or ongoing attacks. If changes are made to the IDPS, but are not saved to the configuration that is loaded upon the next boot-up of the device, the network would be vulnerable to previously mitigated risks. The IDPS must enforce changes to approved authorizations for controlling the flow of information within the network and between interconnected systems by ensuring the device configuration used upon reboot contains the most recent updates made to policy filters, rules, signatures, and anomaly analysis algorithms.

Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident, or identify those responsible for one. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail. The IDPS must have the capability to capture and log detected security violations and potential security violations.

Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident, or identify those responsible for one. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail. The IDPS must have the capability to capture and log events where communications traffic was blocked or restricted because of a security violation or potential security violations.

Without the capability to generate audit records with a severity code it is difficult to track and handle detection events. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail. The IDPS must have the capability to collect and log the severity associated with the policy, rule, or signature. IDSP products often have either pre-configured and/or a configurable method for associating an impact indicator or severity code with signatures and rules, at a minimum.

Without establishing what type of event occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Associating an event types with each event log entry provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured IDPS. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail.

Without establishing the time (date/time) an event occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Associating the date and time the event occurred with each event log entry provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured IDPS. Log records must have accurate date/time stamps since forensic analysis of security incidents and day-to-day monitoring are substantially more difficult if there are no time stamps on log entries. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail.

Without establishing where an event occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Associating event location with the event log entries provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured IDPS. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail. This requirement refers to capturing information about where the event was detected, rather than where the event originated.

Without establishing the source of an event, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Associating the source of the event with detected events in the logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured IDPS. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail.

Without establishing the outcome of the event, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Associating event outcome with detected events in the log provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured IDPS. While auditing and logging are closely related, they are not the same. Logging is recording data about events that take place in a system, while auditing is the use of log records to identify security-relevant information such as system or user accesses. In short, log records are audited to establish an accurate history. Without logging, it would be impossible to establish an audit trail. If harmful or potentially harmful communications traffic is detected, the IDPS must capture all of the traffic associated with the incident for forensic analysis. The logs should identify what servers, operating systems, and applications were attacked and the interaction of the target with the attacker. All commands that were entered by the attacker (such as account creations, changes in permissions, files accessed, etc.) during the session should also be logged.

Without information that establishes the identity of the subjects (i.e., users or processes acting on behalf of users) associated with the events, security personnel cannot determine responsibility for the potentially harmful event. Log record content that may be necessary to satisfy this requirement includes the user or process identifiers.

Without the ability to centrally manage the content captured in the log records, identification, troubleshooting, and correlation of suspicious behavior would be difficult and could lead to a delayed or incomplete analysis of an attack. Centralized management and storage of log records increases efficiency in maintenance and management of records as well as facilitates the backup and archiving of those records. The IDPS must be configured to support centralized management and configuration of the content to be captured in audit records generated by all network components. IDPS sensors and consoles must have the capability to support centralized logging. They must be configured to send log messages to centralized, redundant servers and be capable of being remotely configured to change logging parameters (such as facility and severity levels).

Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading ensures audit information does not get overwritten if the limited audit storage capacity is reached and also protects the audit record in case the system/component being audited is compromised. This also prevents the log records from being lost if the logs stored locally are accidentally or intentionally deleted, altered, or corrupted.

Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading ensures audit information does not get overwritten if the limited audit storage capacity is reached and also protects the audit record in case the system/component being audited is compromised. This also prevents the log records from being lost if the logs stored locally are accidentally or intentionally deleted, altered, or corrupted. IDPS components must have the capability to support centralized logging. They must be configured to send log messages to centralized, redundant servers in real time (within less than a second).

Without a real time alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis and detect rate-based and other anomalies will be impeded. The IDPS must generate an alert which will notify designated personnel of the logging failure. Since SAs or IAOs must take action immediately, these messages will be designated as a critical severity level. Alerts provide organizations with urgent messages. Real time alerts provide these messages immediately (i.e., the time from event detection to alert occurs in seconds or less).

Appropriate personnel must be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. If the IDPS becomes unable to write events to either local storage or to a centralized server, this is a logging failure. This can happen when the local storage is full and the device is not configured to overwrite the oldest record in the file with the newest (circular buffer), or when connectivity to the centralized Syslog server is lost, or when the Syslog process is stopped or hung.

It is critical that when the IDPS is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure. The IDPS performs a critical security function, so its continued operation is imperative. Since availability of the IDPS is an overriding concern, shutting down the system in the event of an audit failure should be avoided, except as a last resort.

It is critical that when the IDPS is at risk of failing to process audit logs as required, it take action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure. The IDPS performs a critical security function, so its continued operation is imperative. Since availability of the IDPS is an overriding concern, shutting down the system in the event of an audit failure should be avoided, except as a last resort.

The loss of log messages compromises the accuracy of audits that use those messages. If log messages are missing, then important information may be missed during an audit. Log messages must be synchronized between the IDPS local storage and the centralized log collection server; the centralized log collection server should store every message that the local device storage stores, otherwise an audit using the log records from the centralized log server may be inaccurate. Audit log records must be sent to a centralized collection server; if communication with this server is lost or the server fails, the IDPS must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action must be taken to synchronize the local audit data with the collection server.

Centralized review and analysis of log records from multiple IDPS components gives the organization the capability to better detect distributed attacks and provides increased data points for behavior analysis techniques. These techniques are invaluable in monitoring for indicators of complex attack patterns. To support the centralized analysis capability, the IDPS components must be able to provide the information in a format (e.g., Syslog) that can be extracted and used, allowing the application to effectively review and analyze the log records.

Configuring the IDPS to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed that affect the security posture and/or functionality of the network element. Security-related parameters are those parameters impacting the security state of the network element, including the parameters required to satisfy other security control requirements. For the network element, security-related parameters include settings for communications traffic management configurations.

An IDPS can be capable of providing a wide variety of capabilities. Not all of these capabilities are necessary. Unnecessary services, functions, and applications increase the attack surface (sum of attack vectors) of a system. These unnecessary capabilities are often overlooked and therefore may remain unsecured.

An IDPS can be capable of providing a wide variety of capabilities. Not all of these capabilities are necessary. Unnecessary services, functions, and applications increase the attack surface (sum of attack vectors) of a system. These unnecessary capabilities are often overlooked and therefore may remain unsecured. This requirement applies to unnecessary features of the IDPS application itself.

Some ports, protocols, or services have known exploits or security weaknesses. These ports, protocols, and services must be prohibited or restricted in the IDPS configuration in accordance with DoD policy. Policy filters restrict traffic destined to the enclave perimeter in accordance with the guidelines contained in DoD Instruction 8551.1 for all ports, protocols, and functions. SAs will review the vulnerability assessment for each port allowed into the enclave and apply all appropriate mitigations defined in the Vulnerability Assessment report. Only ports, protocols, and functions allowed into the enclave should be registered in the PPSM database. It is the responsibility of the enclave owner to have the applications the enclave uses registered in the PPSM database.

Mobile code is defined as software modules obtained from remote systems, transferred across a network, and then downloaded and executed on a local system without explicit installation or execution by the recipient. Examples of mobile code include JavaScript, VBScript, Java applets, ActiveX controls, Flash animations, Shockwave videos, and macros embedded within Microsoft Office documents. Mobile code can be exploited to attack a host. It can be sent as an e-mail attachment or embedded in other file formats not traditionally associated with executable code. While the IDPS cannot replace the anti-virus and host-based IDS (HIDS) protection installed on the network's endpoints, vendor or locally created sensor rules can be implemented, which provide preemptive defense against both known and zero-day vulnerabilities. Many of the protections may provide defenses before vulnerabilities are discovered and rules or blacklist updates are distributed by anti-virus or malicious code solution vendors. To monitor for and detect known prohibited mobile code or approved mobile code that violates permitted usage requirements, the IDPS must implement policy filters, rules, signatures, and anomaly analysis.

Mobile code is defined as software modules obtained from remote systems, transferred across a network, and then downloaded and executed on a local system without explicit installation or execution by the recipient. Examples of mobile code include JavaScript, VBScript, Java applets, ActiveX controls, Flash animations, Shockwave videos, and macros embedded within Microsoft Office documents. Mobile code can be exploited to attack a host. It can be sent as an e-mail attachment or embedded in other file formats not traditionally associated with executable code. While the IDPS cannot replace the anti-virus and host-based IDS (HIDS) protection installed on the network's endpoints, vendor or locally created sensor rules can be implemented, which provide preemptive defense against both known and zero-day vulnerabilities. Many of the protections may provide defenses before vulnerabilities are discovered and rules or blacklist updates are distributed by anti-virus or malicious code solution vendors. To block known prohibited mobile code or approved mobile code that violates permitted usage requirements, the IDPS must implement policy filters, rules, signatures, and anomaly analysis.

Failure to a known safe state helps prevent systems from failing to a state that may cause loss of data or unauthorized access to system resources. Network elements that fail suddenly and with no incorporated failure state planning may leave the hosting system available but with a reduced security protection capability. Preserving information system state information also facilitates system restart and return to the operational mode of the organization with less disruption to mission-essential processes. If the IDPS fails in an unsecure manner (open), unauthorized traffic originating externally to the enclave may enter, or the device may permit unauthorized information release. Fail secure is a condition achieved by employing information system mechanisms to ensure, in the event of a device initialization failure, device shutdown failure, or an abort failure of the IDPS, it does not enter into an unsecure state where intended security properties no longer hold. If the device fails, it must not fail in a manner that will allow unauthorized access. If the IDPS fails for any reason, it must stop forwarding traffic altogether or maintain the configured security policies. If the device stops forwarding traffic, maintaining network availability would be achieved through device redundancy. Since it is usually not possible to test this capability in a production environment, systems should either be validated in a testing environment or prior to installation. This requirement is usually a function of the design of the IDPS component. Compliance can be verified by acceptance/validation processes or vendor attestation.

If the IDPS (or any other network element) crashes, it is important for Systems Administrators to be able to identify why the device crashed. Retaining the configuration and log records provides information that can be used to identify the cause of the crash and determine what, if any, other parts of the system may have been affected. The device should also create a file containing the recorded state of the working memory and/or other useful information concerning the crash. This provides additional diagnostic information but may need to be enabled in the device configuration. Network availability is maintained, in part, by the use of redundant components in an architecture that maintains operation of the network in case a component fails. The degree of redundancy depends on mission requirements and operational constraints. Each enclave should also maintain sufficient spares of each device or component and maintain device configurations that can be readily accessed by authorized personnel in case of a device failure. In many cases, the failed device can be immediately placed back into service. To facilitate this, the device must maintain its configuration if it crashes. Since it is usually not possible to test this capability in a production environment, systems should either be validated in a testing environment or prior to installation. This requirement is usually a function of the design of the IDPS component. Compliance can be verified by acceptance/validation processes or vendor attestation.

If the network does not provide safeguards against DoS attack, network resources will be unavailable to users. Installation of IDPS detection and prevention components (i.e., sensors) at key boundaries in the architecture mitigates the risk of DoS attacks. These attacks can be detected by matching observed communications traffic with patterns of known attacks and monitoring for anomalies in traffic volume/type. Detection components that use rate-based behavior analysis can detect attacks when signatures for the attack do not exist or are not installed. These attacks include zero-day attacks which are new attacks for which vendors have not yet developed signatures. Rate-based behavior analysis can detect sophisticated, Distributed DoS (DDoS) attacks by correlating traffic information from multiple network segments or components. This requirement applies to the communications traffic functionality of the IDPS as it pertains to handling communications traffic, rather than to the IDPS device itself.

If the network does not provide safeguards against DoS attack, network resources will be unavailable to users. Installation of IDPS detection and prevention components (i.e., sensors) at key boundaries in the architecture mitigates the risk of DoS attacks. These attacks can be detected by matching observed communications traffic with patterns of known attacks. Detection components that use pattern recognition pre-processors can detect attacks when signatures for the attack do not exist or are not installed. These attacks include zero-day attacks which are new attacks for which vendors have not yet developed signatures. This requirement applies to the communications traffic functionality of the IDPS as it pertains to handling communications traffic, rather than to the IDPS device itself.

If the network does not provide safeguards against DoS attack, network resources will be unavailable to users. Installation of IDPS detection and prevention components (i.e., sensors) at key boundaries in the architecture mitigates the risk of DoS attacks. These attacks can be detected by matching observed communications traffic with patterns of known attacks and monitoring for anomalies in traffic volume, type, or protocol usage. Detection components that use signatures can detect known attacks by using known attack signatures. Signatures are usually obtained from and updated by the IDPS component vendor. These attacks include SYN-flood, ICMP-flood, and Land Attacks. This requirement applies to the communications traffic functionality of the IDPS as it pertains to handling communications traffic, rather than to the IDPS device itself.

DoS attacks can take multiple forms but have the common objective of overloading or blocking a network or host to deny or seriously degrade performance. If the network does not provide safeguards against DoS attack, network resources will be unavailable to users. Installation of IDPS detection and prevention components (i.e., sensors) at key boundaries in the architecture mitigates the risk of DoS attacks. These attacks can be detected by matching observed communications traffic with patterns of known attacks and monitoring for anomalies in traffic volume/type. The IDPS must include protection against DoS attacks that originate from inside the enclave which can affect either internal or external systems. These attacks may use legitimate or rogue endpoints from inside the enclave. These attacks can be simple “floods” of traffic to saturate circuits or devices, malware that consumes CPU and memory on a device or causes it to crash, or a configuration issue that disables or impairs the proper function of a device. For example, an accidental or deliberate misconfiguration of a routing table can misdirect traffic for multiple networks. To comply with this requirement, the IDPS must protect outbound traffic for indications of known and unknown DoS attacks. Sensor log capacity management along with techniques which prevent the logging of redundant information during an attack also guard against DoS attacks.

Since the IDPS is a boundary protection device, if the IDPS fails in an unsecure manner (open), unauthorized traffic originating externally to the enclave may enter, or the device may permit unauthorized information release. Fail secure is a condition achieved by employing information system mechanisms to ensure that if the IDPS traffic monitoring and detection functions fail, it does not enter into a non-secure state where configured security properties no longer hold. If the device fails, it must not fail in a manner that will allow unauthorized access. If the IDPS traffic monitoring and detection functions fail for any reason, the IDPS must stop forwarding traffic altogether or maintain the configured security policies. If the device stops forwarding traffic, maintaining network availability can be achieved through device redundancy. Since it is usually not possible to test this capability in a production environment, systems should either be validated in a testing environment or prior to installation. This requirement is usually a function of the design of the IDPS component. Compliance can be verified by acceptance/validation processes or vendor attestation.

Packet fragmentation is allowed by the TCP/IP specifications and is encouraged in situations where it is needed. However, packet fragmentation has been used to make some attacks harder to detect (by placing them within fragmented packets), and unusual fragmentation has also been used as a form of attack. For example, some network-based attacks have used packets that should not exist in normal communications, such as sending some fragments of a packet but not the first fragment, or sending packet fragments that overlap each other. These, and other types of packet fragmentation, aim to evade the IDPS. Since it is usually not possible to test this capability in a production environment, systems should either be validated in a testing environment or prior to installation. This requirement is usually a function of the design of the IDPS component. Compliance can be verified by acceptance/validation processes or vendor attestation.

Internet Control Message Protocol (ICMP) messages are used to provide feedback about problems in the network. These messages are sent back to the sender to support diagnostics. However, some messages can also provide host information and network topology that may be exploited by an attacker. An IDPS must be configured to “silently drop” the packet and not send an ICMP control message back to the source. In some cases, it may be necessary to direct the traffic to a null interface. Three ICMP messages are commonly used by attackers for network mapping: Destination Unreachable, Redirect, and Address Mask Reply. These responses must be blocked on external interfaces; however, blocking the Destination Unreachable response will prevent Path Maximum Transmission Unit Discovery (PMTUD), which relies on the response “ICMP Destination Unreachable—Fragmentation Needed but DF Bit Set”. PMTUD is a useful function and should only be “broken” after careful consideration. An acceptable alternative to blocking all Destination Unreachable responses is to filter Destination Unreachable messages generated by the IDPS to allow ICMP Destination Unreachable—Fragmentation Needed but DF Bit Set (Type 3, Code 4) and apply this filter to the external interfaces.

Internet Control Message Protocol (ICMP) messages are used to provide feedback about problems in the network. These messages are sent back to the sender to support diagnostics. However, some messages can also provide host information, network topology, and a covert channel that may be exploited by an attacker. Given the prevalence of ICMP traffic on the network, monitoring for malicious ICMP traffic would be cumbersome. Vendors provide signatures and rules which filter for known ICMP traffic exploits.

Failing to automatically update malicious code protection mechanisms, including application software files, signature definitions, and vendor-provided rules, leaves the system vulnerable to exploitation by recently developed attack methods and programs. An automatic update process ensures this important task is performed without the need for SA intervention. The IDPS is a key malicious code protection mechanism in the enclave infrastructure. To ensure this protection is responsive to changes in malicious code threats, IDPS components must be automatically updated, including anti-virus signatures, detection heuristics, vendor-provided rules, and vendor-provided signatures. If a DoD patch management server or update repository having the tested/verified updates is available for the IDPS component, the components must be configured to automatically check this server/site for updates and install new updates. If a DoD server/site is not available, the component must be configured to automatically check a trusted vendor site for updates. A trusted vendor is either commonly used by DoD, specifically approved by DoD, the vendor from which the equipment was purchased, or approved by the local program's CCB.

Failing to update malicious code protection mechanisms, including application software files, signature definitions, and vendor-provided rules, leaves the system vulnerable to exploitation by recently developed attack methods and programs. The IDPS is a key malicious code protection mechanism in the enclave infrastructure. To ensure this protection is responsive to changes in malicious code threats, IDPS components must be updated, including application software files, anti-virus signatures, detection heuristics, vendor-provided rules, and vendor-provided signatures. Updates must be installed in accordance with the CCB procedures for the local organization. However, at a minimum: 1. Updates designated as critical security updates by the vendor must be installed immediately. 2. Updates for signature definitions, detection heuristics, and vendor-provided rules must be installed immediately. 3. Updates for application software are installed in accordance with the CCB procedures. 4. Prior to automatically installing updates, either manual or automated integrity and authentication checking is required, at a minimum, for application software updates.

If the integrity of updates downloaded directly from the vendor is not verified, then malicious code or errors may impact the ability of the IDPS to protect against harmful communication traffic. The recommended verification method depends on the update’s format, as follows: 1. For files downloaded from a Web site or FTP site, administrators should compare file checksums provided by the vendor with checksums that they compute for the downloaded files. 2. For updates downloaded automatically through the IDPS user interface, if an update is downloaded as a single file or a set of files, either checksum provided by the vendor should be compared to checksums generated by the administrator, or the IDPS user interface itself should perform some sort of integrity check. In some cases, updates are downloaded and installed as one action, precluding checksum verification. In this case, the IDPS user interface should check each update’s integrity as part of this process. 3. In the case of removable media (e.g., CD, DVD), vendors may not provide a specific method for customers to verify the legitimacy of removable media apparently sent by the vendors. If media verification is a concern, administrators should contact their vendors to determine how the media can be verified, such as comparing vendor-provided checksums to checksums computed for files on the media, or verifying digital signatures on the media’s contents to ensure they are valid. Administrators should also consider scanning the media for malware, with the caveat that false positives may be triggered by IDPS signatures for malware on the media.

Real-time monitoring of files from external sources at network entry/exit points helps to detect covert malicious code before it is downloaded to or executed by internal and external endpoints. Using malicious code, such as viruses, worms, Trojan horses, and spyware, an attacker may gain access to sensitive data and systems. IDPSs innately meet this requirement for real time scanning for malicious code when properly configured to meet the requirements of this SRG. However, most products perform communications traffic inspection at the packet level.

Taking an appropriate action based on local organizational incident handling procedures minimizes the impact of this code on the network. The IDPS must be configured to block all detected malicious code. Sometimes it is necessary to generate a log event and then automatically delete the malicious code; however, for critical attacks or where forensic evidence is deemed necessary, the file should be quarantined for further investigation.

Without an alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis and detect rate-based and other anomalies will be impeded. The IDPS generates an alert which notifies designated personnel of the incident. These messages should include a severity level indicator or code as an indicator of the criticality of the incident.

An integrated, network-wide intrusion detection capability increases the ability to detect and prevent sophisticated distributed attacks based on access patterns and characteristics of access. Integration is more than centralized logging and a centralized management console. The enclave's monitoring capability may include multiple sensors, IPS, sensor event databases, behavior-based monitoring devices, application-level content inspection systems, malicious code protection software, scanning tools, audit record monitoring software, and network monitoring software. Some tools may monitor external traffic while others monitor internal traffic at key boundaries. These capabilities may be implemented using different devices and therefore can have different security policies and severity-level schema. This is valuable because content filtering, monitoring, and prevention can become a bottleneck on the network if not carefully configured.

Unauthorized or unapproved network services lack organizational verification or validation and therefore may be unreliable or serve as malicious rogues for valid services. Examples of network services include service-oriented architectures (SOAs), cloud-based services (e.g., infrastructure as a service, platform as a service, or software as a service), cross-domain, Voice Over Internet Protocol, Instant Messaging, auto-execute, and file sharing. To comply with this requirement, the IDPS may be configured to detect services either directly or indirectly (i.e., by detecting traffic associated with a service).

Unauthorized or unapproved network services lack organizational verification or validation and therefore may be unreliable or serve as malicious rogues for valid services. Appropriate personnel must be notified when such unauthorized services are detected. Examples of network services include service-oriented architectures (SOAs), cloud-based services (e.g., infrastructure as a service, platform as a service, or software as a service), cross-domain, Voice Over Internet Protocol, Instant Messaging, auto-execute, and file sharing.

Unauthorized or unapproved network services lack organizational verification or validation and therefore may be unreliable or serve as malicious rogues for valid services. Appropriate personnel must be notified when such unauthorized services are detected. Automated mechanisms can be used to send automatic alerts or notifications. Such automatic alerts or notifications can be conveyed in a variety of ways (e.g., telephonically, via electronic mail, via text message, or via websites). The IDPS must either send the alert to a management console that is actively monitored by authorized personnel or use a messaging capability to send the alert directly to designated personnel.

If inbound communications traffic is not continuously monitored for unusual/unauthorized activities or conditions, there will be times when hostile activity may not be noticed and defended against. Although some of the components in the site's content scanning solution may be used for periodic scanning assessment, the IDPS sensors and other components must provide continuous, 24 hours a day, 7 days a week monitoring. Unusual/unauthorized activities or conditions related to information system inbound communications traffic include, for example, internal traffic that indicates the presence of malicious code within organizational information systems or propagating among system components, the unauthorized exporting of information, or signaling to external information systems. Anomalies within organizational information systems include, for example, large file transfers, long-time persistent connections, use of unusual protocols and ports, and communications with suspected or known malicious external entities.

If outbound communications traffic is not continuously monitored for unusual/unauthorized activities or conditions, there will be times when hostile activity may not be noticed and defended against. Although some of the components in the site's content scanning solution may be used for periodic scanning assessment, the IDPS sensors and other components must provide continuous, 24 hours a day, 7 days a week monitoring. Unusual/unauthorized activities or conditions related to information system outbound communications traffic include, for example, internal traffic that indicates the presence of malicious code within organizational information systems or propagating among system components, the unauthorized exporting of information, or signaling to external information systems. Anomalies within organizational information systems include, for example, large file transfers, long-time persistent connections, use of unusual protocols and ports, and communications with suspected or known malicious external entities.

Without an alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis and detect rate-based and other anomalies will be impeded. The IDPS generates an alert which notifies designated personnel of the incident. These messages should include a severity level indicator or code as an indicator of the criticality of the incident. In accordance with CCI-001242, real-time, the IDPS is a real-time intrusion detection system. These systems must generate an alert when detection events from real-time monitoring occur. Alerts may be transmitted, for example, telephonically, by electronic mail messages, or by text messaging. The IDPS must either send the alert to a management console that is actively monitored by authorized personnel or use a messaging capability to send the alert directly to designated personnel.

Without an alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis and detect rate-based and other anomalies will be impeded. The IDPS generates an alert which notifies designated personnel of the incident. These messages should include a severity level indicator or code as an indicator of the criticality of the incident. Alerts may be transmitted, for example, telephonically, by electronic mail messages, or by text messaging. The IDPS must either send the alert to a management console that is actively monitored by authorized personnel or use a messaging capability to send the alert directly to designated personnel.

Without an alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis and detect rate-based and other anomalies will be impeded. The IDPS generates an alert which notifies designated personnel of the incident. These messages should include a severity level indicator or code as an indicator of the criticality of the incident. CJCSM 6510.01B, “Cyber Incident Handling Program”, lists nine Cyber Incident and Reportable Event Categories. Indications of a category 1, 2, 4, or 7 detection event. Category 1 - Root Level Intrusion (Incident) Category 2 - User Level Intrusion (Incident) Category 4 - Denial of Service (Incident) Category 7 - Malicious Logic (Incident) Alerts may be transmitted, for example, telephonically, by electronic mail messages, or by text messaging. The IDPS must either send the alert to a management console that is actively monitored by authorized personnel or use a messaging capability to send the alert directly to designated personnel.