CVE-2012-0355 in ASA
Summary
by MITRE
Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services Module (ASASM) in Cisco Catalyst 6500 series devices, with software 8.4 before 8.4(2.11) and 8.5 before 8.5(1.4) allow remote attackers to cause a denial of service (device reload) via (1) IPv4 or (2) IPv6 packets that trigger syslog message 305006, aka Bug ID CSCts39634.
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Analysis
by VulDB Data Team • 05/15/2025
The vulnerability described in CVE-2012-0355 affects Cisco Adaptive Security Appliances (ASA) 5500 series devices and the ASA Services Module (ASASM) in Cisco Catalyst 6500 series devices. This issue represents a critical denial of service weakness that can be exploited by remote attackers to force device reloads, thereby disrupting network security operations. The vulnerability specifically impacts software versions 8.4 before 8.4(2.11) and 8.5 before 8.5(1.4), making these particular releases highly susceptible to exploitation. The flaw manifests through both IPv4 and IPv6 packet transmission, indicating a protocol-agnostic attack vector that increases the potential impact across diverse network environments. This vulnerability is particularly concerning as it directly affects network security infrastructure devices that serve as critical boundary protection mechanisms for enterprise networks.
The technical mechanism behind this vulnerability involves the processing of specific IPv4 or IPv6 packets that trigger syslog message 305006 within the affected Cisco ASA devices. When these packets are received, they cause the device to enter a state that results in automatic device reload, effectively creating a denial of service condition. The trigger mechanism operates at the network protocol level, where malformed or specially crafted packets can cause the ASA to crash and restart. This behavior stems from inadequate input validation and error handling within the packet processing modules of the affected software versions. The vulnerability is classified as a buffer overflow or memory corruption issue that occurs during packet inspection, leading to the device's inability to maintain stable operation under normal network traffic conditions. This type of flaw aligns with CWE-121, which describes heap-based buffer overflow conditions that can be exploited to cause system instability.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network security postures. When an ASA device reloads due to exploitation, it temporarily removes all network security protections that the device was providing, leaving the network segment it protects vulnerable to attacks. Network administrators face the challenge of maintaining security coverage while dealing with the potential for frequent device restarts, which can occur during active network traffic periods. The vulnerability affects both IPv4 and IPv6 traffic, meaning that organizations cannot simply disable one protocol to mitigate the risk, and must address the underlying software flaw. Additionally, the remote nature of the attack means that threat actors do not require physical access or network credentials to exploit this weakness, making it particularly dangerous for organizations with exposed network security appliances.
Organizations should prioritize immediate remediation efforts by upgrading to software versions that address this vulnerability, specifically versions 8.4(2.11) and 8.5(1.4) or later. The mitigation strategy should include implementing network access controls to limit exposure of affected devices to untrusted networks, while also monitoring syslog messages for the specific 305006 alerts that indicate exploitation attempts. Network segmentation and redundancy planning become critical elements in mitigating the impact of such vulnerabilities, ensuring that device failures do not cascade across the entire network infrastructure. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for Network Denial of Service, representing a specific method for achieving persistent service disruption against network security infrastructure. The vulnerability also aligns with the broader category of T1566 for initial access through social engineering and network infrastructure compromise, as it represents a potential entry point for attackers seeking to establish persistent access through network infrastructure disruption. Security teams should also consider implementing network monitoring solutions that can detect and alert on anomalous packet patterns that may indicate exploitation attempts, while maintaining regular patch management processes to ensure all network security devices remain protected against known vulnerabilities.