CVE-2025-43973 in GoBGP
Summary
by MITRE • 04/21/2025
An issue was discovered in GoBGP before 3.35.0. pkg/packet/rtr/rtr.go does not verify that the input length corresponds to a situation in which all bytes are available for an RTR message.
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Analysis
by VulDB Data Team • 07/23/2025
The vulnerability identified as CVE-2025-43973 affects GoBGP versions prior to 3.35.0 and resides within the packet handling component of the software. This issue specifically concerns the RTR protocol implementation in the file pkg/packet/rtr/rtr.go where insufficient input validation occurs during the processing of RTR messages. The flaw represents a critical security gap that could potentially allow malicious actors to exploit improper length verification mechanisms within the BGP routing protocol implementation.
The technical flaw manifests as a lack of proper input validation for RTR message lengths in the GoBGP software stack. When processing incoming RTR messages, the system fails to ensure that the complete message data is available before attempting to parse or process the message content. This condition creates a potential buffer over-read or under-read scenario where the application may attempt to access memory locations beyond the actual received data boundaries. The vulnerability stems from inadequate bounds checking and validation of message length parameters, which are fundamental requirements for secure network protocol implementations.
From an operational perspective, this vulnerability poses significant risks to BGP routing infrastructure that relies on GoBGP for network traffic management. Attackers could potentially craft malformed RTR messages that exploit the length verification gap to cause denial of service conditions, unexpected application behavior, or even potential code execution depending on the specific implementation details. The impact extends beyond simple service disruption as it could compromise the integrity of routing information exchange, potentially leading to routing loops, traffic redirection, or unauthorized access to network infrastructure components.
The vulnerability aligns with CWE-129 Input Validation and Man-in-the-Middle attack patterns as described in the MITRE CWE database, representing a classic case of insufficient input length validation. It also maps to ATT&CK technique T1071.004 Application Layer Protocol and T1499.004 Endpoint Denial of Service within the Enterprise ATT&CK framework. Organizations using affected GoBGP versions should prioritize immediate remediation through the application of the 3.35.0 release or equivalent patches that address the input validation gap in the RTR message processing component.
Security practitioners should implement network monitoring to detect anomalous RTR message patterns that might indicate exploitation attempts. Additionally, the vulnerability highlights the importance of comprehensive input validation in network protocol implementations and underscores the need for regular security assessments of routing software components. The fix in version 3.35.0 specifically addresses the missing length verification checks and ensures that all bytes required for proper RTR message processing are available before proceeding with message parsing operations. Organizations should conduct thorough testing of patched environments to ensure that legitimate RTR message processing continues to function correctly while the vulnerability has been resolved.