CVE-2012-0356 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 7.0 through 7.2 before 7.2(5.7), 8.0 before 8.0(5.27), 8.1 before 8.1(2.53), 8.2 before 8.2(5.8), 8.3 before 8.3(2.25), 8.4 before 8.4(2.5), and 8.5 before 8.5(1.2) and the Firewall Services Module (FWSM) 3.1 and 3.2 before 3.2(23) and 4.0 and 4.1 before 4.1(8) in Cisco Catalyst 6500 series devices, when multicast routing is enabled, allow remote attackers to cause a denial of service (device reload) via a crafted IPv4 PIM message, aka Bug IDs CSCtr47517 and CSCtu97367.
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Analysis
by VulDB Data Team • 03/21/2021
The vulnerability described in CVE-2012-0356 represents a critical denial of service flaw affecting Cisco Adaptive Security Appliances and related firewall modules. This weakness specifically targets devices running Cisco's ASA software versions 7.0 through 8.5 and FWSM modules version 3.1 through 4.1 when multicast routing is enabled. The flaw manifests through the processing of crafted IPv4 Protocol Independent Multicast (PIM) messages, which can trigger device reloads and render the affected systems unavailable. The vulnerability affects both hardware platforms including the ASA 5500 series and the ASA Services Module within Cisco Catalyst 6500 series devices, as well as the Firewall Services Module in the same Catalyst platforms.
The technical implementation of this vulnerability stems from inadequate input validation within the multicast routing processing functionality of Cisco's security appliances. When these devices receive specially crafted PIM messages, the malformed packets cause the routing engine to crash and subsequently reload the entire system. This occurs because the software fails to properly sanitize or validate the incoming multicast routing information before processing it, creating a condition where malicious actors can exploit the system's handling of these specific packet structures. The vulnerability operates at the network protocol level and specifically targets the multicast routing protocol implementation within the Cisco ASA and FWSM software stacks. According to CWE classification, this represents a weakness in input validation and error handling, specifically CWE-129 and CWE-20, which fall under the broader category of improper input validation leading to resource exhaustion or system instability. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1499.004, which involves network disruption through denial of service attacks targeting network infrastructure components.
The operational impact of CVE-2012-0356 is severe and potentially devastating for organizations relying on Cisco security appliances for network protection. A successful exploitation of this vulnerability results in complete service disruption as affected devices undergo automatic reload cycles, effectively removing them from network operations until manual intervention occurs. This denial of service condition can persist until the device is manually restarted or the software is patched, creating potential windows of network exposure and operational downtime. Organizations using these affected devices in critical network segments face significant risks including loss of network monitoring capabilities, potential bypass of security controls, and disruption of business continuity operations. The vulnerability affects multiple generations of Cisco security appliances, making it particularly concerning for large enterprise networks where these devices typically serve as primary security gateways and traffic filters. The impact extends beyond simple service interruption to potentially compromise network security posture, as the reload process may temporarily remove the device from the security infrastructure.
Mitigation strategies for this vulnerability require immediate implementation of software updates and patches provided by Cisco. Organizations should prioritize upgrading their affected ASA and FWSM devices to versions that contain the necessary fixes, specifically targeting the software releases mentioned in the CVE description. The recommended approach includes implementing the appropriate Cisco security advisories and applying the patches during scheduled maintenance windows to minimize operational disruption. Network administrators should also consider implementing temporary network segmentation or access controls to limit exposure while patches are deployed. Additionally, monitoring network traffic for anomalous PIM message patterns can help detect potential exploitation attempts. Security teams should also implement proper change management processes to ensure all affected devices receive timely updates. The vulnerability highlights the importance of maintaining current software versions and following vendor security recommendations. Organizations should also consider implementing network intrusion detection systems that can identify and alert on suspicious multicast traffic patterns that may indicate exploitation attempts. Compliance with industry standards such as NIST SP 800-53 and ISO 27001 requires maintaining updated security configurations and addressing known vulnerabilities promptly to ensure adequate protection of network infrastructure.