Cisco ASA IPS Security Technical Implementation Guide

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.

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.

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 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.

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.

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 that prevent the logging of redundant information during an attack, also guards 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.

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.

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

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.

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