CVE-2001-0650 in IOS
Summary
by MITRE
Cisco devices IOS 12.0 and earlier allow a remote attacker to cause a crash, or bad route updates, via malformed BGP updates with unrecognized transitive attribute.
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Analysis
by VulDB Data Team • 12/15/2024
Cisco IOS versions 12.0 and earlier contain a critical vulnerability in their Border Gateway Protocol implementation that allows remote attackers to disrupt network operations through malformed BGP updates. This vulnerability specifically affects the handling of transitive attributes within BGP messages, where the system fails to properly validate incoming route updates containing unrecognized transitive attributes. The flaw exists in the protocol parsing logic that does not adequately sanitize or reject malformed BGP update messages, leading to potential system instability.
The technical nature of this vulnerability stems from insufficient input validation within the IOS BGP routing daemon. When a malicious actor sends a BGP update message containing unrecognized transitive attributes, the router's processing routine encounters unexpected data structures that trigger memory corruption or invalid state transitions. This behavior aligns with CWE-129, Input Validation, and CWE-248, Uncaught Exception, as the system does not properly handle malformed input data. The vulnerability operates at the network layer and affects the routing protocols that maintain network connectivity and traffic flow.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network integrity and availability. Remote attackers can leverage this weakness to cause denial of service conditions by crashing routing processes or injecting malformed route information that leads to incorrect routing decisions. This could result in network partitions, traffic blackholing, or complete routing table corruption that affects multiple network segments. The vulnerability particularly impacts network infrastructure reliability and can be exploited to create cascading failures across interconnected networks, aligning with ATT&CK technique T1498.001, Network Denial of Service.
Mitigation strategies should focus on immediate patching of affected IOS versions to address the BGP validation logic flaws. Network administrators should implement BGP update filtering mechanisms and route validation policies to prevent malformed updates from reaching vulnerable devices. Additionally, deploying monitoring solutions that can detect unusual BGP update patterns and implementing network segmentation strategies can help contain potential exploitation attempts. The vulnerability demonstrates the importance of robust input validation in network protocol implementations and highlights the need for comprehensive security testing of routing protocols to prevent similar issues in future deployments.