CVE-2008-2732 in PIX
Summary
by MITRE
Multiple unspecified vulnerabilities in the SIP inspection functionality in Cisco PIX and Adaptive Security Appliance (ASA) 5500 devices 7.0 before 7.0(7)16, 7.1 before 7.1(2)71, 7.2 before 7.2(4)7, 8.0 before 8.0(3)20, and 8.1 before 8.1(1)8 allow remote attackers to cause a denial of service (device reload) via unknown vectors, aka Bug IDs CSCsq07867, CSCsq57091, CSCsk60581, and CSCsq39315.
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Analysis
by VulDB Data Team • 08/16/2019
The vulnerability identified as CVE-2008-2732 represents a critical security flaw within the Session Initiation Protocol (SIP) inspection capabilities of Cisco PIX and Adaptive Security Appliance (ASA) 5500 series devices. This issue affects multiple software versions including 7.0 through 8.1, specifically before the mentioned patch releases, creating a substantial window of exposure for organizations relying on these security appliances for network protection. The vulnerability manifests through unspecified vectors that exploit the SIP inspection functionality, which is essential for managing VoIP traffic and ensuring proper session establishment between communication endpoints.
The technical nature of this vulnerability lies within the processing of SIP inspection rules and the handling of malformed or specially crafted SIP packets that traverse the affected Cisco devices. When these devices encounter specific SIP traffic patterns, the inspection engine fails to properly validate or process the incoming packets, leading to a condition that causes the device to crash and subsequently reload. This behavior constitutes a remote denial of service attack where an unauthenticated attacker can disrupt network services without requiring administrative credentials or physical access to the device. The vulnerability's impact extends beyond simple service disruption as it can potentially be leveraged to create persistent availability issues that affect voice communication services and network infrastructure reliability.
From an operational standpoint, this vulnerability poses significant risks to organizations that depend on SIP-based voice services and unified communications systems. The device reload behavior effectively removes the security appliance from service, creating a window where network traffic bypasses critical security controls and potentially exposing the network to additional threats. The attack vectors remain unspecified in the public disclosure, which means defenders cannot easily predict or implement specific network-level protections against the exact methods of exploitation. This lack of specificity also complicates the development of effective intrusion detection signatures and makes the vulnerability particularly dangerous as it can be exploited without prior knowledge of the exact attack pattern. The vulnerability's presence in multiple software versions across the 7.0, 7.1, 7.2, 8.0, and 8.1 release lines indicates a fundamental flaw in the SIP inspection implementation that affected a broad user base within the Cisco security appliance ecosystem.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of the relevant security patches released by Cisco, specifically targeting versions 7.0(7)16, 7.1(2)71, 7.2(4)7, 8.0(3)20, and 8.1(1)8. The mitigation strategy should include comprehensive testing of the patches in controlled environments before deployment to ensure compatibility with existing network configurations and services. Network administrators should also implement monitoring solutions to detect potential exploitation attempts and establish incident response procedures for device reload events. According to CWE standards, this vulnerability aligns with CWE-119 which addresses weaknesses in memory handling and buffer overflows, while the ATT&CK framework would categorize this under the T1499.004 technique for network disruption attacks and potentially T1071.004 for application layer protocols. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such attacks and maintain redundant security appliances to minimize service disruption during patching operations.