CVE-2013-2236 in Quagga
Summary
by MITRE
Stack-based buffer overflow in the new_msg_lsa_change_notify function in the OSPFD API (ospf_api.c) in Quagga before 0.99.22.2, when --enable-opaque-lsa and the -a command line option are used, allows remote attackers to cause a denial of service (crash) via a large LSA.
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Analysis
by VulDB Data Team • 01/08/2022
The vulnerability identified as CVE-2013-2236 represents a critical stack-based buffer overflow within the Open Shortest Path First Daemon implementation of Quagga routing software. This flaw exists in the new_msg_lsa_change_notify function located in the OSPF API component, specifically within the ospf_api.c file. The vulnerability manifests when the Quagga daemon is compiled with the --enable-opaque-lsa configuration option and subsequently executed with the -a command line argument, creating a dangerous combination that exposes the system to remote exploitation. The flaw operates by failing to properly validate input data length when processing Link State Advertisement (LSA) notifications, allowing malicious actors to craft oversized LSA messages that exceed the allocated stack buffer space.
The technical nature of this vulnerability places it squarely within the CWE-121 category of stack-based buffer overflow conditions, where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the program stack. This particular implementation flaw occurs during the processing of OSPF LSA change notifications, which are fundamental components of the OSPF routing protocol used for exchanging network topology information between routers. When the daemon receives a malformed LSA message containing excessive data, the new_msg_lsa_change_notify function fails to validate the incoming data size against the predetermined buffer limits, resulting in a classic stack overflow scenario. The overflow causes the program to crash and terminate unexpectedly, leading to a denial of service condition that disrupts network routing operations and potentially affects the entire network infrastructure.
From an operational perspective, this vulnerability poses significant risks to network availability and stability since OSPF daemons are critical components in routing infrastructure. The remote exploitation capability means that attackers can trigger the denial of service condition without requiring local access or authentication, making it particularly dangerous in production environments. Network administrators face the challenge of maintaining routing stability while the vulnerable Quagga versions continue to operate in network environments. The impact extends beyond simple service disruption as the crash can cause routing table inconsistencies, potential network partitions, and require manual intervention to restore normal operations. The vulnerability affects all versions of Quagga prior to 0.99.22.2, representing a substantial window of exposure for organizations relying on this widely deployed routing software.
The exploitation of this vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks, where adversaries leverage software flaws to disrupt network services. Security professionals should consider this vulnerability in their threat modeling exercises for network infrastructure components. Mitigation strategies include immediate patching to Quagga version 0.99.22.2 or later, which contains the necessary code fixes to properly validate LSA message sizes. Organizations should also implement network segmentation and access controls to limit exposure, while monitoring for suspicious LSA traffic patterns. Additionally, the vulnerability highlights the importance of proper input validation in network protocol implementations and demonstrates the necessity of thorough security testing for routing daemon software. The fix implemented in the patched version addresses the core buffer overflow issue by introducing proper bounds checking mechanisms that ensure LSA message data does not exceed allocated buffer boundaries, thereby preventing the stack corruption that leads to daemon crashes.