CVE-2012-0353 in ASA
Summary
by MITRE
The UDP inspection engine on Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services Module (ASASM) in Cisco Catalyst 6500 series devices, with software 8.0 before 8.0(5.25), 8.1 before 8.1(2.50), 8.2 before 8.2(5.5), 8.3 before 8.3(2.22), 8.4 before 8.4(2.1), and 8.5 before 8.5(1.2) does not properly handle flows, which allows remote attackers to cause a denial of service (device reload) via a crafted series of (1) IPv4 or (2) IPv6 UDP packets, aka Bug ID CSCtq10441.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability described in CVE-2012-0353 represents a critical flaw in the UDP inspection engine of Cisco Adaptive Security Appliances (ASA) and ASA Services Module (ASASM) devices. This issue affects multiple software versions across the ASA 5500 series and Catalyst 6500 series devices, specifically targeting versions prior to the listed patch releases. The flaw manifests in the improper handling of network flows within the UDP inspection mechanism, creating a condition where specially crafted UDP packets can trigger unexpected behavior in the device's processing logic. The vulnerability operates at the network protocol level, specifically targeting the stateful inspection capabilities that are fundamental to the security appliance's operation.
The technical implementation of this vulnerability involves the manipulation of UDP packet sequences that cause the device's inspection engine to enter an erroneous state. When processing legitimate UDP traffic, the device fails to properly maintain flow state information or handle edge cases in packet processing, leading to a cascade of errors that ultimately results in system instability. The attack vector requires remote exploitation through network-accessible interfaces, allowing attackers to send malicious UDP packets to the affected devices without requiring physical access or authentication credentials. This type of vulnerability falls under CWE-129, which deals with insufficient input validation, and specifically relates to improper handling of network flow states in security appliances.
The operational impact of this vulnerability is severe, as it can result in complete device downtime through unauthorized device reloads. When exploited successfully, the vulnerability forces the affected Cisco ASA or ASASM device to restart its operating system, effectively removing it from service and disrupting network connectivity for all users relying on the security infrastructure. This denial of service condition can be particularly devastating in enterprise environments where these devices serve as primary network security gateways, potentially affecting thousands of users and critical business operations. The attack can be executed with minimal resources and does not require specialized tools beyond basic network packet crafting capabilities, making it an attractive vector for both opportunistic and targeted attacks.
Organizations affected by this vulnerability should immediately implement mitigation strategies including applying the relevant software patches released by Cisco, which address the flow handling issues in the UDP inspection engine. Network segmentation and access control measures should be strengthened to limit the attack surface, while monitoring systems should be enhanced to detect anomalous UDP traffic patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security appliance firmware and highlights the risks associated with running legacy software versions in production environments. From an ATT&CK framework perspective, this vulnerability maps to techniques involving denial of service and privilege escalation, as it allows remote attackers to disrupt services and potentially gain unauthorized access to network infrastructure through system instability. Regular security assessments and vulnerability management programs become essential to prevent similar issues from compromising network security infrastructure.