CVE-2009-4913 in ASA 5580
Summary
by MITRE
The IPv6 implementation on Cisco Adaptive Security Appliances (ASA) 5580 series devices with software before 8.1(2) exposes IP services on the "far side of the box," which might allow remote attackers to bypass intended access restrictions via IPv6 packets, aka Bug ID CSCso58622.
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Analysis
by VulDB Data Team • 04/20/2017
The vulnerability described in CVE-2009-4913 represents a critical security flaw in Cisco Adaptive Security Appliances running software versions prior to 8.1(2). This issue specifically affects the IPv6 implementation on Cisco ASA 5580 series devices, creating an unexpected exposure of IP services that fundamentally undermines the device's primary security function. The vulnerability stems from improper handling of IPv6 packets within the network security appliance's architecture, allowing unauthorized access to services that should remain isolated within the internal network segments.
The technical flaw manifests when the ASA device processes IPv6 packets that contain specific routing or addressing information, enabling attackers to reach services that are typically protected by the firewall's access control policies. This occurs because the IPv6 implementation fails to properly enforce the intended network segmentation that separates internal and external network zones. The vulnerability is particularly concerning as it allows remote attackers to bypass access restrictions that should normally be enforced by the security appliance, effectively creating a backdoor access path through the device's own network stack implementation.
The operational impact of this vulnerability extends beyond simple network access bypass, as it represents a fundamental failure in the security appliance's ability to maintain network boundaries. Attackers can exploit this flaw to gain access to internal network services that should only be reachable through legitimate network paths, potentially leading to full network compromise. The vulnerability affects the core functionality of the ASA device, which is designed to enforce security policies and protect network infrastructure from unauthorized access, making it a critical concern for network administrators and security professionals.
This vulnerability aligns with CWE-284, which describes improper access control in network security implementations, and demonstrates how flaws in protocol handling can undermine fundamental security mechanisms. The attack vector is particularly dangerous as it requires no local access or authentication, allowing remote exploitation through crafted IPv6 packets that can be sent from anywhere on the internet. From an ATT&CK framework perspective, this vulnerability maps to techniques involving network infiltration and privilege escalation, as it enables attackers to move laterally within networks by bypassing security controls that should prevent such access.
Organizations affected by this vulnerability should immediately implement mitigation strategies including upgrading to Cisco ASA software version 8.1(2) or later, which contains the necessary patches to address the IPv6 implementation flaw. Network administrators should also consider implementing additional monitoring and logging mechanisms to detect unusual IPv6 traffic patterns that might indicate exploitation attempts. The recommended approach involves comprehensive network security assessments to identify any potential exposure and ensuring that all network security appliances are updated to versions that properly handle IPv6 traffic according to industry security standards and best practices.