CVE-2013-1794 in OpenAFS
Summary
by MITRE
Buffer overflow in certain client utilities in OpenAFS before 1.6.2 allows remote authenticated users to cause a denial of service (crash) and possibly execute arbitrary code via a long fileserver ACL entry.
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Analysis
by VulDB Data Team • 01/01/2022
The vulnerability identified as CVE-2013-1794 represents a critical buffer overflow condition within OpenAFS client utilities that affects versions prior to 1.6.2. This flaw exists in the handling of fileserver Access Control List entries where client applications fail to properly validate input length before processing potentially maliciously crafted ACL data. The buffer overflow occurs when the client utility processes an excessively long ACL entry, causing memory corruption that can lead to application crashes or potentially arbitrary code execution.
OpenAFS, a distributed filesystem implementation, relies heavily on proper input validation and memory management to maintain system integrity. The vulnerability specifically targets client-side utilities that parse ACL entries from file servers, making it particularly dangerous in environments where authenticated users have access to file systems with extensive permission structures. The flaw allows an attacker with valid authentication credentials to exploit this condition remotely, leveraging their legitimate access to cause system instability or gain elevated privileges.
The technical exploitation of this vulnerability involves crafting a maliciously long ACL entry that exceeds the allocated buffer space within the client utility's memory management. When the client processes this oversized entry, it overflows the designated buffer and potentially corrupts adjacent memory regions, leading to unpredictable behavior. This type of vulnerability falls under CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The impact extends beyond simple denial of service to include potential code execution scenarios, particularly when the overflow affects control flow information such as return addresses or function pointers.
From an operational perspective, this vulnerability creates significant risk for organizations relying on OpenAFS distributed filesystems, as it allows authenticated attackers to disrupt service availability or escalate privileges. The attack vector requires only valid authentication credentials, making it particularly concerning for environments where access controls might be insufficiently enforced. Security teams must consider the implications of this vulnerability within the context of the ATT&CK framework, specifically under the T1068 technique for exploiting vulnerabilities and T1499 for network denial of service attacks. The vulnerability's potential for arbitrary code execution places it in a high-risk category for organizations that do not maintain current patch levels.
Mitigation strategies for CVE-2013-1794 primarily focus on immediate patch deployment to OpenAFS versions 1.6.2 and later, which contain proper bounds checking and input validation mechanisms. Organizations should implement comprehensive patch management processes to ensure all client utilities receive updates promptly. Additional defensive measures include monitoring for unusual ACL entry lengths, implementing network segmentation to limit access to critical file servers, and establishing robust access control policies that minimize the attack surface for authenticated users. The vulnerability demonstrates the importance of maintaining current software versions and implementing proper input validation practices in distributed filesystem implementations, as buffer overflow conditions remain among the most prevalent and dangerous classes of security flaws in enterprise environments.