CVE-2012-0957 in Linux
Summary
by MITRE
The override_release function in kernel/sys.c in the Linux kernel before 3.4.16 allows local users to obtain sensitive information from kernel stack memory via a uname system call in conjunction with a UNAME26 personality.
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Analysis
by VulDB Data Team • 10/20/2024
The vulnerability described in CVE-2012-0957 represents a significant information disclosure flaw within the Linux kernel's system call handling mechanism. This issue affects Linux kernel versions prior to 3.4.16 and specifically targets the override_release function located in kernel/sys.c. The vulnerability arises from improper memory management during the processing of uname system calls when combined with the UNAME26 personality setting, creating a pathway for local attackers to access sensitive kernel stack memory contents.
The technical flaw stems from the insufficient validation and memory clearing mechanisms within the override_release function. When a local user executes a uname system call with the UNAME26 personality configured, the kernel fails to properly sanitize stack memory regions that should not be exposed to user-space applications. This occurs because the function does not adequately clear or protect kernel stack memory areas that contain sensitive data, potentially including cryptographic keys, passwords, or other confidential information that may have been present in those memory locations during previous operations. The vulnerability is particularly dangerous because it leverages legitimate system calls to achieve information disclosure, making it difficult to detect through normal security monitoring.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with access to potentially sensitive kernel memory contents that could be exploited in subsequent attacks. Local users who can execute the specific combination of uname system call with UNAME26 personality can extract valuable data from kernel stack memory, which may include remnants of passwords, cryptographic tokens, or other confidential information processed by the kernel. This information disclosure could facilitate privilege escalation attacks or provide attackers with additional intelligence for more sophisticated exploitation techniques. The vulnerability affects all systems running Linux kernel versions before 3.4.16, making it a widespread concern across numerous deployments and applications.
The remediation for this vulnerability requires updating to Linux kernel version 3.4.16 or later, which includes patches that properly address the memory handling issues in the override_release function. System administrators should prioritize this update across all affected systems, particularly those running older kernel versions where the vulnerability remains present. Additionally, organizations should implement comprehensive monitoring to detect any suspicious uname system call activity combined with UNAME26 personality settings, as this specific combination represents the attack vector for this vulnerability. The fix addresses the underlying CWE-248 weakness related to exposure of sensitive information and helps mitigate potential ATT&CK techniques involving information gathering and privilege escalation through kernel memory access. Organizations should also review their kernel configuration and ensure that unnecessary personality settings are disabled to minimize the attack surface for similar vulnerabilities.