CVE-2012-0255 in Quagga
Summary
by MITRE
The BGP implementation in bgpd in Quagga before 0.99.20.1 does not properly use message buffers for OPEN messages, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a message associated with a malformed Four-octet AS Number Capability (aka AS4 capability).
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/24/2024
The vulnerability identified as CVE-2012-0255 affects the Border Gateway Protocol implementation within Quagga's bgpd daemon, specifically targeting versions prior to 0.99.20.1. This flaw resides in the handling of OPEN messages within the BGP protocol implementation, which serves as the foundational protocol for routing between autonomous systems on the internet. The issue manifests when the system processes malformed Four-octet AS Number Capability messages, which are part of the BGP capability advertisement mechanism that allows routers to negotiate supported features and extensions.
The technical root cause involves improper buffer management during the processing of OPEN messages containing malformed Four-octet AS Number Capability data. When a remote attacker crafts and sends a specially crafted BGP OPEN message with invalid AS4 capability information, the bgpd daemon fails to properly validate or handle the malformed data structure. This deficiency leads to an assertion failure within the software's internal validation mechanisms, causing the daemon to terminate unexpectedly. The vulnerability specifically targets the buffer allocation and usage patterns in the BGP message parsing code, where insufficient bounds checking or improper memory management allows malicious input to trigger system instability.
The operational impact of this vulnerability is significant as it enables remote attackers to execute a denial of service attack against BGP routers running affected Quagga versions. When the daemon exits due to the assertion failure, it disrupts the routing functionality of the affected system, potentially causing network partitions or complete loss of BGP connectivity within the autonomous system. This attack requires minimal privileges and can be executed from any network location capable of establishing a BGP session with the vulnerable router. The daemon's termination creates a cascading effect that may impact downstream routing decisions and network stability, particularly in large-scale deployments where BGP stability is critical for maintaining network connectivity.
Mitigation strategies for CVE-2012-0255 involve immediate patching of Quagga installations to version 0.99.20.1 or later, which contains the necessary buffer management fixes and input validation improvements. Network administrators should also implement BGP session filtering and access control lists to limit BGP peer relationships to trusted sources, reducing the attack surface. Additionally, monitoring systems should be configured to detect unusual daemon restart patterns or BGP session flapping that may indicate exploitation attempts. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and relates to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing network segmentation and BGP monitoring tools to detect and respond to malformed BGP messages before they can cause daemon termination.