CVE-2005-3276 in Linux
Summary
by MITRE
The sys_get_thread_area function in process.c in Linux 2.6 before 2.6.12.4 and 2.6.13 does not clear a data structure before copying it to userspace, which might allow a user process to obtain sensitive information.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/14/2019
The vulnerability described in CVE-2005-3276 represents a classic information disclosure flaw in the Linux kernel's thread management subsystem. This issue affects kernel versions prior to 2.6.12.4 and 2.6.13, specifically within the sys_get_thread_area function located in the process.c file. The flaw stems from insufficient data sanitization during kernel-to-userspace data transfer operations, creating a potential pathway for unauthorized information exposure.
The technical root cause of this vulnerability lies in the improper handling of data structures during the sys_get_thread_area system call execution. When a user process invokes this system call to retrieve thread area information, the kernel function fails to properly clear or initialize the data structure before copying it to userspace. This incomplete sanitization means that sensitive information from kernel memory may remain accessible to user processes through the returned data structure. The vulnerability manifests as a classic information leak where remnants of kernel data structures could contain confidential information such as kernel addresses, internal state data, or other sensitive metadata that should not be exposed to user-space applications.
From an operational perspective, this vulnerability presents significant security implications for systems running affected kernel versions. An attacker could potentially exploit this flaw to gain insights into the kernel's internal memory layout, which could facilitate more sophisticated attacks such as privilege escalation or bypass of security mechanisms. The information disclosure could reveal kernel addresses that might be used in return-oriented programming attacks or other exploitation techniques. The vulnerability's impact is particularly concerning in environments where multiple users or untrusted processes are running, as it could enable a malicious user to gather information that would normally be protected by kernel isolation mechanisms.
The vulnerability aligns with CWE-200, which addresses "Information Exposure," and relates to the broader category of information leakage vulnerabilities that compromise system security. From an ATT&CK framework perspective, this weakness maps to T1005 - Data from Local System and T1059 - Command and Scripting Interpreter, as it enables adversaries to gather system information that could be used for further exploitation. The flaw demonstrates the critical importance of proper data sanitization in kernel space operations, particularly when transferring data between privileged and unprivileged contexts. The issue underscores the necessity of maintaining strict isolation boundaries between kernel and user space, as even seemingly benign system calls can become attack vectors when proper security practices are not followed.
Mitigation strategies for this vulnerability primarily involve upgrading to kernel versions 2.6.12.4 or 2.6.13, which contain the necessary patches to properly clear data structures before userspace access. System administrators should prioritize this upgrade, especially in production environments where security is paramount. Additionally, monitoring for suspicious system call patterns or unexpected data access could help detect exploitation attempts, though the vulnerability itself is more about information exposure than active exploitation. Organizations should also consider implementing additional security controls such as kernel hardening measures, proper access controls, and regular security audits to minimize the attack surface and protect against similar vulnerabilities that may arise from insufficient data sanitization practices in kernel code.