CVE-2013-1218 in Intrusion Prevention System
Summary
by MITRE
Cisco Intrusion Prevention System (IPS) Software in ASA 5500-X IPS-SSP software modules before 7.1(7)sp1E4 allows remote attackers to cause a denial of service (Analysis Engine process hang or device reload) via fragmented (1) IPv4 or (2) IPv6 packets, aka Bug ID CSCue51272.
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Analysis
by VulDB Data Team • 05/18/2021
The vulnerability identified as CVE-2013-1218 affects Cisco Intrusion Prevention System software running on ASA 5500-X series security appliances, specifically impacting the IPS-SSP software modules. This flaw represents a significant security concern as it enables remote attackers to execute denial of service attacks against network infrastructure. The vulnerability manifests when the Analysis Engine process becomes unresponsive or the entire device requires a reload, effectively compromising network availability and operational continuity. The issue stems from improper handling of fragmented IPv4 and IPv6 packets within the IPS processing pipeline, creating a condition where legitimate network traffic can be exploited to disrupt security operations.
The technical nature of this vulnerability resides in the way the IPS software processes fragmented packets, which falls under the category of improper input validation and resource handling. When the system receives specially crafted fragmented IPv4 or IPv6 packets, the Analysis Engine component fails to properly manage the packet reassembly process, leading to a hang condition or system restart. This behavior aligns with CWE-129, which addresses improper validation of input ranges, and CWE-248, which covers exposure of an exception to an unauthorized actor. The vulnerability demonstrates a classic case of insufficient error handling where malformed packet fragments cause the system to enter an unstable state rather than gracefully rejecting or properly processing the malformed data.
From an operational impact perspective, this vulnerability presents a substantial risk to network security infrastructure as it allows attackers to remotely disrupt critical security services without requiring authentication or privileged access. The denial of service condition affects the primary function of the IPS module, which is to monitor and protect network traffic from malicious activity. When the Analysis Engine hangs or the device reloads, network administrators lose the ability to detect and prevent intrusion attempts, creating a window of vulnerability where the network becomes more susceptible to attacks. This attack vector is particularly dangerous because it can be executed from outside the network perimeter, making it an attractive target for adversaries seeking to disrupt business operations or create conditions for more sophisticated attacks.
The attack surface for this vulnerability extends beyond simple network disruption as it can be leveraged as a precursor to more complex attack scenarios. Security professionals must consider that an attacker could use this vulnerability to create a distraction while launching other attacks, or to target specific network segments where the affected appliances are deployed. The vulnerability affects the broader security ecosystem by potentially compromising the integrity of network monitoring and intrusion detection capabilities. Organizations should note that the impact extends beyond immediate service disruption to include potential data loss, compliance violations, and reputational damage if the denial of service attacks are prolonged or occur during critical business periods.
Mitigation strategies for CVE-2013-1218 should prioritize immediate software updates to versions 7.1(7)sp1E4 or later, which contain the necessary patches to address the fragmented packet handling issue. Network administrators should implement additional monitoring and alerting mechanisms to detect unusual patterns in packet processing that might indicate exploitation attempts. The mitigation approach should also include network segmentation strategies to limit the potential impact of successful attacks and ensure that critical network services remain available even if individual appliances are compromised. Organizations should consider implementing redundant security appliances and establishing incident response procedures specifically designed to handle denial of service attacks targeting security infrastructure. Additionally, network traffic filtering rules can be implemented to reduce the volume of fragmented packets entering the network, though this approach should be carefully balanced against legitimate network traffic requirements. The remediation process should also include comprehensive testing of updated software in controlled environments before deployment to production systems to ensure that the patches do not introduce compatibility issues with existing network configurations.