CVE-2022-26126 in FRRouting
Summary
by MITRE • 03/03/2022
Buffer overflow vulnerabilities exist in FRRouting through 8.1.0 due to the use of strdup with a non-zero-terminated binary string in isis_nb_notifications.c.
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Analysis
by VulDB Data Team • 11/05/2025
The vulnerability identified as CVE-2022-26126 represents a critical buffer overflow flaw within FRRouting software version 8.1.0 and earlier. This issue stems from improper handling of string operations within the isis_nb_notifications.c source file where the strdup function is employed with binary data that lacks proper null termination. The fundamental problem occurs when the software processes network notifications related to Intermediate System to Intermediate System (IS-IS) routing protocol communications, creating an exploitable condition that can lead to arbitrary code execution or system compromise.
The technical implementation of this vulnerability manifests through the use of strdup function which expects null-terminated strings but receives binary data from network packets or configuration inputs. When the software processes IS-IS notifications containing non-null-terminated binary content, the strdup operation fails to properly terminate the copied string, resulting in memory corruption that can be exploited by attackers. This flaw directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability is particularly concerning as it occurs during the processing of network notifications, making it accessible through normal network communication channels without requiring special privileges.
Operational impact of this vulnerability extends beyond simple denial of service conditions to encompass full system compromise and potential lateral movement within network infrastructures. Attackers can craft malicious IS-IS notifications that trigger the buffer overflow when processed by vulnerable FRRouting instances, potentially leading to remote code execution. This creates significant risk for network infrastructure devices that rely on FRRouting for IS-IS protocol implementation, including routers and switches that form the backbone of enterprise and service provider networks. The vulnerability affects systems where IS-IS routing is actively configured and operational, making it particularly dangerous in production environments where these routing protocols are actively exchanging information between network devices.
Mitigation strategies for CVE-2022-26126 should prioritize immediate software updates to FRRouting version 8.1.1 or later, which contain the necessary patches to address the buffer overflow condition. Network administrators should also implement network segmentation and access controls to limit exposure of vulnerable routing devices to untrusted networks. Additional protective measures include implementing monitoring for unusual IS-IS notification patterns and configuring input validation to reject malformed binary data before it reaches the vulnerable code paths. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving remote code execution through protocol manipulation and privilege escalation via network infrastructure compromise. Organizations should also consider implementing network traffic analysis tools to detect and prevent exploitation attempts targeting this specific vulnerability in their routing infrastructure deployments.