A critical vulnerability in FRRouting allows unauthenticated remote attackers to trigger a Denial of Service attack via crafted OSPF packets, potentially impacting network routing stability.

The vulnerability is a NULL pointer dereference flaw located in the ospf_ext.c source file. An unauthenticated attacker can trigger this condition by sending a specifically crafted OSPF packet to the affected system.

The exploit leads to a crash of the FRRouting service, resulting in a Denial of Service for network routing functions. Given the CVSS score of 7.5, this high-severity flaw poses a significant risk to operational continuity, as a successful exploit could disrupt critical network infrastructure and inter-router communications.

Immediate Action: Review the FRRouting project repository and apply the upstream fix commit (88f5c06cbc1cc4d62e1cba3e7791f5cea4179ba5) or upgrade to the latest stable release containing the patch.

Proactive Monitoring: Monitor system logs for unexpected service restarts or OSPF-related process crashes and evaluate network traffic for anomalous OSPF packets.

Compensating Controls: Implement access control lists (ACLs) to restrict OSPF peering and traffic to authorized and trusted network infrastructure nodes only.

Public Exploit Available: Yes — a published proof-of-concept exists, attributed to the technical write-up referenced in the CVE record.

This vulnerability presents a clear risk to routing stability by allowing unauthenticated remote disruption of the FRRouting service. IT administrators must prioritize identifying and patching all instances of FRRouting within the environment. Until patches can be verified and deployed, ensure that OSPF traffic is strictly limited to known, trusted interfaces to reduce the attack surface.