Intrusion Detection and Prevention Systems Security Requirements Guide

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 IDPS enforces approved authorizations by controlling the flow of information between interconnected networks to prevent harmful or suspicious traffic does spread to these interconnected networks. Information flow control policies and restrictions govern where information is allowed to travel as opposed to who is allowed to access the information. The IDPS includes 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. IDPS components are installed and configured such that they restrict or block detected harmful or suspect information flows 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, including upon restart or the application or reboot of the system. 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.

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 type with each event log entry provides a means of investigating an attack 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 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.

Associating where the event was detected with the event log entries provides a means of investigating an attack or identifying an improperly configured IDPS. This information can be used to determine what systems may have been affected. 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.

Associating the source of the event with detected events in the logs provides a means of investigating an attack or suspected attack. 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.

Associating event outcome with detected events in the log provides a means of investigating an attack or suspected attack. 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 logs should identify what servers, destination addresses, applications, or databases were potentially attacked by logging communications traffic between the target and 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.

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 SYSLOG protocol does not support automated synchronization, however this functionality may be provided by Network Management Systems (NMSs) which are not within the scope of this SRG.

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. 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.

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.

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. IDPS 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.

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. System administrators 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.

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. 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. To comply with this requirement, the IDPS must inspect 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. This requirement is used in conjunction with other requirements which require configuration of security policies, signatures, rules, and anomaly detection techniques and are applicable to both inbound and outbound traffic.

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. 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. This requirement applies to the device itself, not the network traffic. Abort refers to stopping a program or function before it has finished naturally. The term abort refers to both requested and unexpected terminations. 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.

Failure in a secure state address safety or security in accordance with the mission needs of the organization. Failure to a secure state helps prevent a loss of confidentiality, integrity, or availability in the event of a failure of the information system or a component of the system. Preserving state information helps to facilitate the restart of the IDPS application and a return to operation with minimum disruption. This requirement applies to a failure of the IDPS function rather than the device or operating system as a whole which is addressed in the Network Device Management SRG. 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.

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, antivirus 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.

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.

Configuring the IDPS to delete and/or quarantine based on local organizational incident handling procedures minimizes the impact of this code on the network.

Configuring the network element to delete and/or quarantine based on local organizational incident handling procedures minimizes the impact of this code on the network. Malicious code includes, but is not limited to, viruses, worms, Trojan horses, and spyware. The code provides the ability for a malicious user to read from and write to files and folders on a computer's hard drive. Malicious code may also be able to run and attach programs, which may allow the unauthorized distribution of malicious mobile 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 preferred action is for the file to be quarantined for further investigation. This requirement is limited to network elements that perform security functions, such as ALG and IDPS.

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 immediate (within seconds) alert which notifies designated personnel of the incident. Sending a message to an unattended log or console does not meet this requirement since that will not be seen immediately. These messages should include a severity level indicator or code as an indicator of the criticality of the incident.

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 system administrator 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.

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.

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.

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.

Without an alert, security personnel may be unaware of an impending failure of the audit capability, and the ability to perform forensic analysis may be impeded. This requirement includes, but is not limited to, failures where the detection and/or prevention function is unable to write events to either local storage or the centralized server. The IDPS must generate an alert which will notify designated personnel of the logging failure. Alerts provide organizations with urgent messages. The alert must provide these messages immediately (i.e., the time from event detection to alert occurs in seconds or less). Alert messages must include the severity level. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSO.

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. Since action must be taken immediately, these messages will be designated as a critical severity level and this level must be sent as part of the alert message.

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 anomaly-based attack detection 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.

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. 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. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSO to the vulnerability discussion.

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 intrusion detection incidents that require immediate action and this delay may result in the loss or compromise of information. In accordance with CCI-001242, 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSM and ISSO.

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. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSM and ISSO.

Without an alert, security personnel may be unaware of major detection incidents that require immediate action and this delay may result in the loss or compromise of information. CJCSM 6510.01B, "Cyber Incident Handling Program", lists nine Cyber Incident and Reportable Event Categories. DoD has determined that categories identified by CJCSM 6510.01B Major Indicators (category I, II, IV, and VII detection events) will require an alert when an event is detected. Alerts messages must include a severity level indicator or code as an indicator of the criticality of the incident. Since these incidents require immediate action, these messages are assigned a critical or level 1 priority/severity, depending on the system's priority schema. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSM and ISSO.

Without an alert, security personnel may be unaware of major detection incidents that require immediate action and this delay may result in the loss or compromise of information. CJCSM 6510.01B, "Cyber Incident Handling Program", lists nine Cyber Incident and Reportable Event Categories. DoD has determined that categories identified by CJCSM 6510.01B Major Indicators (category I, II, IV, and VII detection events) will require an alert when an event is detected. Alerts messages must include a severity level indicator or code as an indicator of the criticality of the incident. Since these incidents require immediate action, these messages are assigned a critical or level 1 priority/severity, depending on the system's priority schema. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSM and ISSO.

Without an alert, security personnel may be unaware of major detection incidents that require immediate action and this delay may result in the loss or compromise of information. CJCSM 6510.01B, "Cyber Incident Handling Program", lists nine Cyber Incident and Reportable Event Categories. DoD has determined that categories identified by CJCSM 6510.01B Major Indicators (category I, II, IV, and VII detection events) will require an alert when an event is detected. Alerts messages must include a severity level indicator or code as an indicator of the criticality of the incident. Since these incidents require immediate action, these messages are assigned a critical or level 1 priority/severity, depending on the system's priority schema. 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. The ISSM or ISSO may designate the system administrator or other authorized personnel to receive the alert within the specified time, validate the alert, then forward only validated alerts to the ISSM and ISSO.

Without an alert, security personnel may be unaware of major detection incidents that require immediate action and this delay may result in the loss or compromise of information. CJCSM 6510.01B, "Cyber Incident Handling Program", lists nine Cyber Incident and Reportable Event Categories. DoD has determined that categories identified by CJCSM 6510.01B Major Indicators (category I, II, IV, and VII detection events) will require an alert when an event is detected. Alerts messages must include a severity level indicator or code as an indicator of the criticality of the incident. Since these incidents require immediate action, these messages are assigned a critical or level 1 priority/severity, depending on the system's priority schema. 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.

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.

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. Off-loading is a common process in information systems with limited audit storage capacity. The audit storage on the IDPS is used only in a transitory fashion until the system can communicate with the centralized log server designated for storing the audit records, at which point the information is transferred. However, DoD requires that the log be transferred in real-time which indicates that the time from event detection to off-loading is seconds or less. This does not apply to audit logs generated on behalf of the device itself (management).

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.

DoS events may occur due to a variety of internal and external causes, such as an attack by an adversary or a lack of planning to support organizational needs with respect to capacity and bandwidth. Such attacks can occur across a wide range of network protocols (e.g., IPv4, IPv6). A variety of technologies are available to limit or eliminate the origination and effects of DoS events. For example, boundary protection devices can filter certain types of packets to protect system components on internal networks from being directly affected by or the source of DoS attacks. Employing increased network capacity and bandwidth combined with service redundancy also reduces the susceptibility to DoS events.

Separating critical system components and functions from other noncritical system components and functions through separate subnetworks may be necessary to reduce susceptibility to a catastrophic or debilitating breach or compromise that results in system failure. For example, physically separating the command and control function from the in-flight entertainment function through separate subnetworks in a commercial aircraft provides an increased level of assurance in the trustworthiness of critical system functions.

An incident, whether adversarial- or nonadversarial-based, can disrupt established communications paths used for system operations and organizational command and control. Alternate communications paths reduce the risk of all communications paths being affected by the same incident. To compound the problem, the inability of organizational officials to obtain timely information about disruptions or to provide timely direction to operational elements after a communications path incident, can impact the ability of the organization to respond to such incidents in a timely manner. Establishing alternate communications paths for command and control purposes, including designating alternative decision makers if primary decision makers are unavailable and establishing the extent and limitations of their actions, can greatly facilitate the organization's ability to continue to operate and take appropriate actions during an incident.