CVE-2011-3323 in Quagga
Summary
by MITRE
The OSPFv3 implementation in ospf6d in Quagga before 0.99.19 allows remote attackers to cause a denial of service (out-of-bounds memory access and daemon crash) via a Link State Update message with an invalid IPv6 prefix length.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2011-3323 represents a critical flaw in the OSPFv3 routing protocol implementation within Quagga's ospf6d daemon. This issue affects versions prior to 0.99.19 and demonstrates a classic buffer overflow condition that can be exploited remotely to disrupt network operations. The vulnerability specifically targets the handling of Link State Update messages, which are fundamental components of the OSPFv3 protocol used for exchanging routing information between network devices. When an attacker crafts a malicious OSPFv3 Link State Update message containing an invalid IPv6 prefix length, the vulnerable implementation fails to properly validate input parameters before processing them.
The technical exploitation of this vulnerability occurs through improper bounds checking within the ospf6d daemon's packet processing routines. When the daemon receives a malformed Link State Update message with an invalid IPv6 prefix length, it attempts to access memory locations beyond the allocated buffer boundaries. This out-of-bounds memory access triggers a segmentation fault or similar memory corruption error, causing the ospf6d daemon to crash and terminate unexpectedly. The flaw falls under CWE-129, which describes improper validation of array indices, and specifically relates to the improper handling of input validation in network protocol implementations. The vulnerability demonstrates how insufficient input sanitization in routing protocols can create opportunities for denial of service attacks that can severely impact network infrastructure.
The operational impact of this vulnerability extends beyond simple daemon crashes, as it can lead to complete disruption of routing services within networks that rely on OSPFv3 for inter-domain communication. When the ospf6d daemon crashes, the affected router loses its ability to maintain OSPFv3 routing tables, causing routing instability and potential network partitions. Network administrators may experience cascading failures as routing information becomes unavailable, leading to traffic black holes and service degradation across affected network segments. The remote nature of the attack means that adversaries need not have physical access to the network equipment, making this vulnerability particularly dangerous in environments where network devices are exposed to untrusted network traffic. According to ATT&CK framework, this vulnerability maps to T1499.004 for network denial of service and T1595.001 for network infrastructure reconnaissance, as attackers can identify vulnerable systems and exploit them to cause service disruption.
Mitigation strategies for this vulnerability require immediate patching of Quagga installations to version 0.99.19 or later, which contains the necessary input validation fixes. Network administrators should also implement network segmentation and access controls to limit exposure of OSPFv3 routing daemons to untrusted networks, utilizing techniques such as route filtering and authentication mechanisms. Additional defensive measures include monitoring for unusual OSPFv3 traffic patterns and implementing intrusion detection systems that can identify malformed Link State Update messages. The fix typically involves adding proper bounds checking and input validation routines that verify IPv6 prefix lengths against valid ranges before processing them, ensuring that the ospf6d daemon can gracefully handle malformed input without crashing. Organizations should also conduct comprehensive vulnerability assessments to identify all instances of Quagga installations within their network infrastructure and ensure proper patch management procedures are in place to prevent similar vulnerabilities from being exploited in the future.