CVE-2023-38802 in FRR
Summary
by MITRE • 08/29/2023
FRRouting FRR 7.5.1 through 9.0 and Pica8 PICOS 4.3.3.2 allow a remote attacker to cause a denial of service via a crafted BGP update with a corrupted attribute 23 (Tunnel Encapsulation).
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Analysis
by VulDB Data Team • 12/12/2024
FRRouting FRR versions 7.5.1 through 9.0 and Pica8 PICOS version 4.3.3.2 contain a critical vulnerability that enables remote attackers to induce denial of service conditions through manipulation of Border Gateway Protocol BGP update messages. This vulnerability specifically targets the handling of attribute 23 known as Tunnel Encapsulation within BGP routing updates, representing a significant weakness in network infrastructure software that could compromise routing stability and availability across affected systems.
The technical flaw stems from inadequate validation and processing of the Tunnel Encapsulation attribute within BGP update messages. When a malicious actor crafts a specially formatted BGP update containing corrupted attribute 23 data, the affected routing software fails to properly handle this malformed input, leading to system instability and potential complete service disruption. This vulnerability falls under CWE-129 Input Validation and CWE-20 Improper Input Validation, as the system does not adequately verify the integrity and format of incoming BGP attributes before processing them. The flaw demonstrates a classic buffer over-read or improper memory handling scenario where the software attempts to parse corrupted tunnel encapsulation data without sufficient safeguards.
The operational impact of this vulnerability extends beyond simple service interruption to potentially compromise entire routing domains within network infrastructure. Network operators relying on affected FRRouting or Pica8 devices may experience unexpected routing table corruption, session termination, or complete system crashes when processing malicious BGP updates. This represents a significant concern for internet service providers and enterprise networks that depend on stable BGP operations for internet connectivity and traffic routing. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter without requiring local access or authentication credentials, making it particularly dangerous in production environments.
Mitigation strategies for this vulnerability should prioritize immediate software updates to versions that have patched the affected BGP attribute handling code. Network administrators should implement BGP update filtering and validation mechanisms to prevent malformed tunnel encapsulation attributes from reaching vulnerable systems. The use of BGP monitoring tools and anomaly detection systems can help identify suspicious BGP update patterns that may indicate exploitation attempts. According to ATT&CK framework technique T1071.004 Application Layer Protocol: DNS, attackers may leverage such vulnerabilities to disrupt network services, making proactive network segmentation and access controls essential. Additionally, implementing proper BGP route filtering and prefix validation can reduce the attack surface and limit the potential impact of successful exploitation attempts.