CVE-2005-0003 in Linux
Summary
by MITRE
The 64 bit ELF support in Linux kernel 2.6 before 2.6.10, on 64-bit architectures, does not properly check for overlapping VMA (virtual memory address) allocations, which allows local users to cause a denial of service (system crash) or execute arbitrary code via a crafted ELF or a.out file.
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Analysis
by VulDB Data Team • 05/29/2019
The vulnerability described in CVE-2005-0003 represents a critical flaw in the Linux kernel's handling of 64-bit executable formats, specifically affecting versions prior to 2.6.10. This issue resides within the kernel's memory management subsystem where the Virtual Memory Area (VMA) handling logic fails to properly validate memory allocation boundaries when processing 64-bit ELF files. The flaw manifests when the kernel attempts to map executable memory regions for 64-bit applications, creating a scenario where overlapping memory mappings can occur without proper validation checks.
The technical implementation of this vulnerability stems from insufficient boundary checking within the kernel's memory management code that governs how virtual memory areas are allocated and managed. When a crafted 64-bit ELF or a.out file is executed, the kernel's VMA management code does not adequately verify that new memory mappings do not overlap with existing ones, leading to potential memory corruption scenarios. This condition can be exploited by local attackers who craft malicious executable files designed to trigger specific memory allocation patterns that cause the kernel to behave unpredictably. The vulnerability specifically impacts 64-bit architectures where the kernel's 64-bit ELF support is active, making it particularly relevant for systems running older kernel versions on x86_64 or similar 64-bit platforms.
The operational impact of this vulnerability extends beyond simple denial of service to encompass potential arbitrary code execution capabilities. When exploited successfully, the overlapping VMA allocation can cause system crashes through kernel memory corruption, leading to complete system instability and potential denial of service conditions. More critically, the flaw allows local attackers to execute arbitrary code with kernel privileges, effectively elevating their access level from regular user to root level. This represents a significant privilege escalation vulnerability that can be leveraged to compromise entire systems. The vulnerability affects systems where 64-bit ELF support is enabled and the kernel version is below 2.6.10, making it particularly dangerous for enterprise environments running older kernel versions or for systems that have not been properly updated.
Mitigation strategies for this vulnerability focus primarily on kernel version updates to 2.6.10 or later, which contain the necessary patches to properly validate VMA allocations and prevent overlapping memory mappings. System administrators should immediately apply security patches from their distribution vendors to address this issue. Additional protective measures include implementing proper access controls to limit user privileges, monitoring for unusual memory allocation patterns, and maintaining up-to-date system configurations. The vulnerability aligns with CWE-129, which describes improper validation of array indices, and can be mapped to ATT&CK technique T1068, involving the exploitation of system privileges through kernel vulnerabilities. Organizations should also consider implementing kernel module restrictions and monitoring for suspicious executable file patterns that might indicate attempts to exploit this vulnerability. Regular security audits and vulnerability assessments should include verification of kernel versions and memory management configurations to prevent exploitation of similar memory corruption vulnerabilities in the future.