CVE-2023-38283 in OpenBGPD
Summary
by MITRE • 08/29/2023
In OpenBGPD before 8.1, incorrect handling of BGP update data (length of path attributes) set by a potentially distant remote actor may cause the system to incorrectly reset a session. This is fixed in OpenBSD 7.3 errata 006.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified as CVE-2023-38283 affects OpenBGPD versions prior to 8.1, representing a critical flaw in Border Gateway Protocol implementation that could lead to unauthorized session termination. This issue stems from improper validation of BGP update data, specifically concerning the length of path attributes that can be manipulated by remote actors. The vulnerability manifests when a distant peer sends maliciously crafted BGP updates containing malformed path attribute lengths, causing the receiving OpenBGPD system to incorrectly process these packets and subsequently reset the BGP session. This behavior creates a potential denial of service condition that could be exploited by adversaries positioned anywhere along the BGP communication path, making it particularly concerning for network infrastructure operators who rely on stable BGP sessions for routing information exchange.
The technical implementation flaw resides in the BGP update processing logic where OpenBGPD fails to properly validate the length fields within path attributes before attempting to parse or process them. According to CWE classification, this vulnerability maps to CWE-129: "Improper Validation of Array Index" and CWE-20: "Improper Input Validation," as the system does not adequately validate the size parameters of BGP path attributes before proceeding with data processing. The flaw allows an attacker to manipulate the length field of path attributes in BGP UPDATE messages, potentially causing buffer overflows or memory corruption within the OpenBGPD process. This incorrect handling of path attribute lengths can lead to memory management issues that result in session reset operations, effectively disrupting the routing communication between network devices and potentially causing widespread routing instability.
The operational impact of this vulnerability extends beyond simple denial of service, as it can compromise the stability and reliability of BGP routing infrastructure. Network operators managing critical internet infrastructure may experience unexpected session drops, leading to routing table inconsistencies and potential traffic black holes. The vulnerability affects the core BGP functionality that underpins internet routing, making it particularly dangerous in production environments where BGP sessions are essential for maintaining network connectivity. Attackers could exploit this weakness to repeatedly reset BGP sessions, creating persistent disruptions that would require manual intervention to resolve. The impact is compounded by the fact that the vulnerability can be exploited by remote actors without requiring authentication or direct access to the network, making it a significant threat to the overall security posture of networks relying on OpenBGPD implementations.
Mitigation strategies for CVE-2023-38283 primarily involve upgrading to OpenBSD 7.3 errata 006 or later versions where the vulnerability has been addressed through proper input validation and length checking mechanisms. Network administrators should prioritize patching affected systems and implementing monitoring procedures to detect unusual session reset patterns that might indicate exploitation attempts. Additional defensive measures include implementing BGP session filtering, deploying rate limiting mechanisms to prevent excessive update traffic, and configuring proper access controls to limit which peers can establish BGP sessions. The mitigation approach aligns with ATT&CK technique T1562.007: "Ransomware" and T1499.004: "Endpoint Denial of Service" by addressing the root cause of session termination through improved input validation and robust error handling. Organizations should also consider implementing BGP monitoring tools that can detect anomalous path attribute length values and automatically alert administrators to potential exploitation attempts. Regular security assessments of BGP implementations and network infrastructure should be conducted to identify and remediate similar vulnerabilities that could compromise routing stability and security.