CVE-2011-3326 in Quagga
Summary
by MITRE
The ospf_flood function in ospf_flood.c in ospfd in Quagga before 0.99.19 allows remote attackers to cause a denial of service (daemon crash) via an invalid Link State Advertisement (LSA) type in an IPv4 Link State Update message.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2011-3326 represents a critical denial of service flaw within the Open Shortest Path First routing daemon implementation in Quagga software. This issue specifically targets the ospf_flood function located in ospf_flood.c, which is responsible for processing Link State Update messages in the OSPF protocol. The vulnerability arises from inadequate input validation when handling Link State Advertisements, creating a scenario where remote attackers can manipulate routing updates to trigger daemon crashes. The flaw affects Quagga versions prior to 0.99.19, making it a significant concern for network infrastructure relying on this routing software. This vulnerability directly impacts the stability and reliability of OSPF-based network operations, potentially causing widespread disruption to routing services.
The technical implementation of this vulnerability stems from a failure in the ospf_flood function's handling of invalid LSA types within IPv4 Link State Update messages. When an attacker crafts a malicious OSPF packet containing an invalid LSA type, the function processes this malformed data without proper bounds checking or type validation. This processing error leads to memory corruption or unexpected behavior in the routing daemon, ultimately resulting in a crash that terminates the ospfd service. The vulnerability operates at the protocol level, exploiting weaknesses in how OSPF implementations handle malformed routing advertisements. According to CWE classification, this represents a weakness in the validation of input data, specifically CWE-129, which involves insufficient validation of the length or size of input data. The flaw demonstrates characteristics of CWE-20, which covers improper input validation, and CWE-119, concerning weaknesses in memory management that lead to buffer overflows or memory corruption.
The operational impact of CVE-2011-3326 extends beyond simple daemon crashes, creating cascading effects throughout network infrastructure that relies on OSPF routing. When the ospfd daemon crashes, network routers lose their ability to maintain accurate routing tables, leading to potential routing loops, packet loss, and complete network partitioning. This vulnerability particularly affects enterprise networks, service providers, and any infrastructure utilizing Quagga for OSPF routing, as it can be exploited remotely without authentication requirements. The impact aligns with ATT&CK technique T1499.004, which involves network denial of service attacks targeting routing protocols. Network administrators face significant operational challenges when this vulnerability is exploited, as it can cause extended outages and require manual intervention to restore routing services. The vulnerability's remote exploitability means that attackers can target multiple network devices simultaneously, amplifying the potential damage and making it particularly dangerous for large-scale deployments.
Mitigation strategies for CVE-2011-3326 primarily focus on upgrading to Quagga version 0.99.19 or later, which includes proper input validation and error handling for LSA type processing. Network administrators should implement network segmentation and access controls to limit exposure to untrusted networks, as this vulnerability can be exploited from external sources. Additionally, deploying intrusion detection systems that monitor for malformed OSPF packets can provide early warning of potential exploitation attempts. Implementing rate limiting on routing updates and configuring proper logging for OSPF traffic enables better monitoring of anomalous behavior. Organizations should also consider implementing redundant routing daemons or failover mechanisms to minimize service disruption when attacks occur. The vulnerability highlights the importance of input validation in network protocol implementations and serves as a reminder of the critical nature of maintaining up-to-date security patches in routing infrastructure. Compliance with security standards such as those outlined in NIST SP 800-53 and ISO 27001 requires regular vulnerability assessments and prompt remediation of identified weaknesses in network infrastructure components.