CVE-2013-5560 in ASA
Summary
by MITRE
The IPv6 implementation in Cisco Adaptive Security Appliance (ASA) Software 9.1.3 and earlier, when NAT64 or NAT66 is enabled, does not properly process NAT rules, which allows remote attackers to cause a denial of service (device reload) via crafted packets, aka Bug ID CSCue34342.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 12/24/2024
The vulnerability identified as CVE-2013-5560 affects Cisco Adaptive Security Appliance (ASA) Software versions 9.1.3 and earlier, specifically when NAT64 or NAT66 functionality is enabled. This issue represents a critical flaw in the IPv6 processing mechanisms of the ASA platform, where the device fails to properly handle NAT rules when processing IPv6 traffic. The vulnerability manifests as a denial of service condition that can force the device to reload, effectively disrupting network connectivity and security services. The flaw is particularly concerning because it can be exploited remotely through crafted packets, making it accessible to attackers without requiring physical access to the network infrastructure.
The technical root cause of this vulnerability lies in the improper handling of NAT rules within the IPv6 implementation of the ASA software. When NAT64 or NAT66 is enabled, the device should properly translate IPv6 addresses and maintain consistent routing tables, but the flawed implementation fails to adequately process these rules during packet inspection. This misconfiguration leads to a state where specific crafted IPv6 packets can trigger an internal error condition within the ASA's processing engine, causing the device to crash and subsequently reload. The vulnerability specifically affects the packet processing pipeline where IPv6 packets are evaluated against NAT rules, creating a condition where malformed or specially constructed packets can cause memory corruption or state machine failures.
From an operational impact perspective, this vulnerability poses significant risks to network security infrastructure, as the ASA device serves as a critical security gateway in most enterprise environments. A successful exploitation of CVE-2013-5560 can result in complete service disruption, requiring manual intervention to restore the device functionality. The denial of service condition affects not only the availability of network services but also compromises the security posture by removing the device from the network protection chain. Organizations relying on ASA appliances for IPv6 traffic handling, NAT64, or NAT66 functionality face potential exposure to attackers who could leverage this vulnerability to create network outages or disrupt critical business operations.
The vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and relates to the broader category of input validation failures in network security appliances. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for network denial of service, specifically targeting the availability of network infrastructure. The attack vector requires remote access to the network and involves crafting specific IPv6 packets that trigger the device's processing error. Organizations should consider implementing network segmentation and monitoring to detect anomalous packet patterns that might indicate exploitation attempts. The recommended mitigation involves upgrading to Cisco ASA Software versions that address this specific flaw, as well as implementing temporary network controls to restrict IPv6 traffic or disable NAT64/NAT66 functionality until the upgrade can be completed. Additionally, network administrators should monitor for unusual device reload patterns that might indicate exploitation attempts and maintain current security patches to prevent similar vulnerabilities from being exploited in the future.