CVE-2005-3119 in Linux
Summary
by MITRE
Memory leak in the request_key_auth_destroy function in request_key_auth in Linux kernel 2.6.10 up to 2.6.13 allows local users to cause a denial of service (memory consumption) via a large number of authorization token keys.
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Analysis
by VulDB Data Team • 07/04/2019
The vulnerability described in CVE-2005-3119 represents a critical memory management flaw within the Linux kernel's key management subsystem. This issue affects kernel versions 2.6.10 through 2.6.13 and specifically targets the request_key_auth_destroy function which handles the destruction of authorization token keys. The flaw manifests as a memory leak that occurs when the kernel processes a large number of authorization tokens, creating a scenario where allocated memory is not properly released back to the system. This memory consumption issue directly impacts system stability and resource availability.
The technical implementation of this vulnerability lies in the improper handling of kernel memory allocation during the destruction phase of authorization tokens. When the request_key_auth_destroy function processes multiple authorization keys, it fails to correctly deallocate all memory segments associated with these tokens. This creates a gradual accumulation of unreleased memory within the kernel's memory pool, leading to progressive memory exhaustion. The flaw is particularly concerning because it operates at the kernel level where memory management is critical for system performance and stability. According to CWE-401, this represents a classic memory leak vulnerability where the system fails to release allocated resources, and the issue aligns with ATT&CK technique T1499.1 for resource exhaustion attacks.
The operational impact of this vulnerability enables local users to perform a denial of service attack by continuously creating and destroying authorization tokens until system memory becomes exhausted. This attack vector is particularly dangerous because it requires minimal privileges and can be executed by any local user with access to the system. The memory leak accumulates over time, potentially causing system instability, application crashes, or complete system hangs. The vulnerability affects the kernel's ability to manage memory efficiently, leading to reduced system performance and potential system-wide failures. Attackers can exploit this by writing simple scripts that repeatedly create authorization tokens, consuming available memory resources until the system becomes unresponsive or crashes entirely.
Mitigation strategies for CVE-2005-3119 focus primarily on upgrading to patched kernel versions where the memory leak has been corrected. System administrators should immediately apply kernel updates to versions 2.6.14 and later where the vulnerability has been addressed through proper memory deallocation mechanisms in the request_key_auth_destroy function. Additionally, implementing memory monitoring and alerting systems can help detect unusual memory consumption patterns that might indicate exploitation attempts. The kernel configuration should also be reviewed to limit the number of authorization tokens that can be created, providing an additional layer of protection. Organizations should conduct regular security assessments of their kernel versions and maintain up-to-date patch management procedures to prevent similar vulnerabilities from affecting their systems. The fix implemented in patched versions ensures that all memory allocated for authorization tokens is properly released during the destruction process, eliminating the memory leak condition that enabled the denial of service attack.