CVE-2025-43970 in GoBGP
Summary
by MITRE • 04/21/2025
An issue was discovered in GoBGP before 3.35.0. pkg/packet/mrt/mrt.go does not properly check the input length, e.g.. by ensuring that there are 12 bytes or 36 bytes (depending on the address family).
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/23/2025
The vulnerability identified as CVE-2025-43970 represents a critical input validation flaw within the GoBGP software ecosystem, specifically affecting versions prior to 3.35.0. This issue resides in the packet processing module at pkg/packet/mrt/mrt.go, where the software fails to adequately validate the length of incoming data packets. The flaw manifests when processing MRT (Multi-Threaded Routing) packets, which are fundamental components in BGP (Border Gateway Protocol) routing information exchange. The vulnerability stems from insufficient bounds checking that allows malformed packets to bypass initial validation mechanisms, potentially leading to unexpected behavior or system instability.
The technical nature of this vulnerability can be categorized under CWE-129, Input Validation and Canonicalization, and more specifically aligns with CWE-707, Improper Neutralization of Input During Web Page Generation. The flaw occurs because the MRT packet parser does not verify that incoming data contains the expected byte lengths required for proper address family handling. For IPv4 address families, the parser expects 12 bytes of data, while IPv6 address families require 36 bytes of data. When these length requirements are not properly validated, the software may attempt to process truncated or oversized data structures, creating opportunities for memory corruption or unexpected program execution paths.
From an operational perspective, this vulnerability presents significant risks to network infrastructure relying on GoBGP for routing operations. Attackers could exploit this weakness by crafting malicious MRT packets designed to trigger buffer overflows or memory access violations when processed by vulnerable versions. The impact extends beyond simple denial of service, as improper input handling could potentially enable code execution or information disclosure within the routing daemon. Network operators using affected versions face the risk of unauthorized access to routing information or complete service disruption, particularly in environments where automated routing updates are processed without additional validation layers. This vulnerability directly impacts the integrity of BGP routing information exchange, which forms the backbone of internet routing operations.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007, Command and Scripting Interpreter: Python, as attackers might leverage malformed MRT packets to execute unintended code paths within the GoBGP process. Security practitioners should implement immediate mitigation strategies including upgrading to GoBGP version 3.35.0 or later, which includes proper input length validation. Additional protective measures involve deploying network monitoring tools to detect anomalous MRT packet patterns and implementing strict input validation at network boundaries. Organizations should also consider applying network segmentation to limit exposure and ensure that only trusted sources can transmit routing information to affected systems. The remediation process requires thorough testing of updated software to ensure that legitimate routing operations continue unaffected while addressing the underlying validation gap that enabled this vulnerability.