CVE-2008-3802 in IOS
Summary
by MITRE
Unspecified vulnerability in the Session Initiation Protocol (SIP) implementation in Cisco IOS 12.2 through 12.4, when VoIP is configured, allows remote attackers to cause a denial of service (device reload) via unspecified valid SIP messages, aka Cisco bug ID CSCsk42759, a different vulnerability than CVE-2008-3800 and CVE-2008-3801.
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Analysis
by VulDB Data Team • 08/17/2019
The vulnerability described in CVE-2008-3802 represents a critical denial of service weakness within Cisco IOS implementations that affects versions 12.2 through 12.4 when Voice over IP services are enabled. This issue specifically targets the Session Initiation Protocol implementation which serves as the foundation for establishing, modifying, and terminating real-time sessions involving voice, video, and messaging applications. The flaw manifests when legitimate SIP messages are processed by the affected Cisco devices, triggering unexpected behavior that ultimately results in complete device reload operations. This vulnerability operates at the network infrastructure level where SIP traffic is handled, making it particularly dangerous as it can disrupt critical communication services without requiring authentication or privileged access.
The technical nature of this vulnerability stems from improper handling of valid SIP protocol messages within the Cisco IOS software stack. When a malicious actor or unintended condition triggers specific SIP message sequences, the underlying implementation fails to properly validate or process these communications, leading to memory corruption or state management issues that cause the device to crash and subsequently reload its operating system. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, though the exact technical mechanism may involve stack corruption or other memory management failures. The vulnerability's classification as a denial of service rather than an arbitrary code execution flaw means that attackers cannot directly gain unauthorized access to the system, but they can effectively render network services unavailable to legitimate users.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the reliability and availability of voice communication systems within enterprise and service provider networks. When a Cisco device implementing SIP functionality experiences a reload due to this vulnerability, it can result in complete loss of voice services for connected users, potentially affecting business continuity and emergency communication capabilities. Network administrators may face challenges in identifying the root cause of outages since the device appears to crash rather than exhibit clear error conditions. The vulnerability's presence in multiple IOS versions from 12.2 through 12.4 indicates it was likely a fundamental design flaw in the SIP processing code that persisted across several software releases, making it particularly concerning for organizations with legacy systems.
Mitigation strategies for this vulnerability primarily involve applying Cisco's official security patches and software updates that address the specific SIP processing flaws. Organizations should prioritize updating their affected Cisco IOS devices to versions that contain the necessary fixes, typically released as part of Cisco's regular security advisory process. Network segmentation and access control measures can help limit the potential impact by restricting which systems can send SIP messages to vulnerable devices, though this approach does not eliminate the vulnerability itself. The implementation of monitoring solutions that can detect unusual device reload patterns or abnormal SIP traffic may provide early warning capabilities. Additionally, administrators should consider implementing redundant communication paths and backup systems to ensure continued service availability during remediation efforts. This vulnerability demonstrates the importance of maintaining up-to-date security patches and proper network monitoring as outlined in the NIST Cybersecurity Framework and aligns with ATT&CK technique T1499 for disruption of services through denial of service attacks.