CVE-2011-0431 in OpenAFS
Summary
by MITRE
The afs_linux_lock function in afs/LINUX/osi_vnodeops.c in the kernel module in OpenAFS 1.4.14, 1.4.12, 1.4.7, and possibly other versions does not properly handle errors, which allows attackers to cause a denial of service via unknown vectors. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/03/2024
The vulnerability identified as CVE-2011-0431 resides within the OpenAFS kernel module, specifically in the afs_linux_lock function located in the afs/LINUX/osi_vnodeops.c file. This flaw affects multiple versions of OpenAFS including 1.4.14, 1.4.12, and 1.4.7, representing a significant security concern for systems utilizing this distributed file system. OpenAFS is a widely deployed open-source implementation of the Andrew File System that provides scalable network file services, making this vulnerability particularly concerning for enterprise environments that depend on its stability and availability. The vulnerability manifests as improper error handling within the locking mechanism that governs file access operations in the Linux kernel module, creating a potential avenue for malicious actors to disrupt system operations.
The technical nature of this vulnerability stems from the afs_linux_lock function's failure to properly manage error conditions that occur during file locking operations. When errors arise during the locking process, the function does not adequately validate or respond to these exceptional conditions, potentially leading to inconsistent internal state management and resource handling. This improper error handling can result in the kernel module entering an undefined state where subsequent file operations may fail or behave unpredictably. The vulnerability's impact extends beyond simple operational disruption as it can cause cascading failures within the file system's locking infrastructure, potentially affecting multiple concurrent file access operations and leading to broader system instability.
From an operational perspective, this vulnerability presents a significant denial of service risk that can severely impact systems relying on OpenAFS for file storage and access. Attackers can exploit this weakness to cause sustained disruption of file services, potentially affecting hundreds or thousands of users depending on the scale of the deployment. The unspecified attack vectors suggest that the vulnerability may be triggerable through various means including malformed file access requests, concurrent access patterns, or specific timing conditions that cause the error handling to be exercised. The impact can range from temporary service degradation to complete service unavailability, making this a critical concern for mission-critical systems where file service availability is paramount. Organizations using OpenAFS in production environments face potential business disruption and increased operational overhead when this vulnerability is exploited.
The vulnerability aligns with CWE-704, which covers improper error handling in software systems, and represents a classic example of how error management failures can create security weaknesses. From an ATT&CK framework perspective, this vulnerability could be leveraged as part of a broader attack chain to establish persistence or escalate privileges, though the primary impact remains denial of service. Organizations should prioritize patching affected systems with updated OpenAFS versions that address this error handling deficiency, implementing proper monitoring for unusual file access patterns that might indicate exploitation attempts. Additionally, system administrators should consider implementing network segmentation and access controls to limit exposure while patches are deployed, as the vulnerability's impact extends across the entire OpenAFS deployment rather than isolated components. The remediation process should include thorough testing of updated kernel modules to ensure compatibility with existing system configurations and file access patterns.