CVE-2004-1070 in Linux
Summary
by MITRE
The load_elf_binary function in the binfmt_elf loader (binfmt_elf.c) in Linux kernel 2.4.x up to 2.4.27, and 2.6.x up to 2.6.8, does not properly check return values from calls to the kernel_read function, which may allow local users to modify sensitive memory in a setuid program and execute arbitrary code.
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Analysis
by VulDB Data Team • 06/05/2019
The vulnerability identified as CVE-2004-1070 resides within the Linux kernel's ELF binary format loader implementation, specifically in the load_elf_binary function located in the binfmt_elf.c file. This flaw affects kernel versions 2.4.x up to 2.4.27 and 2.6.x up to 2.6.8, representing a critical security issue that undermines the integrity of the kernel's binary loading mechanism. The vulnerability stems from insufficient error handling during file reading operations, creating a potential pathway for privilege escalation attacks.
The technical flaw manifests when the load_elf_binary function fails to properly validate the return values from kernel_read function calls during ELF binary loading processes. This improper error checking allows local attackers to manipulate memory contents in setuid programs, effectively bypassing the security mechanisms that normally protect these privileged executables. The vulnerability is particularly dangerous because it operates within the kernel's core binary loading infrastructure, making it difficult to detect and exploit through conventional means. When the kernel_read function encounters an error condition, the load_elf_binary function does not properly handle this failure, potentially leading to undefined behavior that can be leveraged by malicious actors.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it specifically targets setuid programs that are designed to run with elevated privileges. Attackers can exploit this weakness to modify sensitive memory regions within these privileged processes, potentially gaining unauthorized access to system resources or executing arbitrary code with elevated privileges. This creates a significant threat to system integrity, as the vulnerability allows attackers to circumvent the normal security boundaries that protect critical system functions. The attack vector is particularly insidious because it requires no special privileges beyond local access, making it accessible to any user with shell access to the system.
The vulnerability aligns with CWE-252, which describes "Unchecked Return Value," a weakness that occurs when a function's return value is not properly checked, potentially leading to unexpected behavior. This flaw also maps to ATT&CK technique T1068, "Local Privilege Escalation," as it enables attackers to exploit system weaknesses to gain elevated privileges. Additionally, the vulnerability demonstrates characteristics of T1548.001, "Abuse Elevation Control Mechanism," where attackers manipulate system controls to bypass security restrictions. The exploitation of this vulnerability requires a deep understanding of kernel memory management and binary loading processes, making it a sophisticated attack vector that targets fundamental system components.
Mitigation strategies for CVE-2004-1070 primarily focus on updating to patched kernel versions where the return values from kernel_read calls are properly validated. System administrators should immediately apply security patches released by kernel maintainers, as the vulnerability affects widely deployed kernel versions. Additional protective measures include implementing proper system hardening practices such as disabling unnecessary setuid programs, monitoring for suspicious memory access patterns, and employing kernel security modules that can detect anomalous behavior. The vulnerability also highlights the importance of comprehensive error handling in kernel code and underscores the need for rigorous code review processes to identify similar issues in system-level components. Regular security audits of kernel modules and binary loaders should be conducted to prevent similar vulnerabilities from being introduced in future releases.