CVE-2004-1074 in Linux
Summary
by MITRE
The binfmt functionality in the Linux kernel, when "memory overcommit" is enabled, allows local users to cause a denial of service (kernel oops) via a malformed a.out binary.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability described in CVE-2004-1074 resides within the Linux kernel's binary format handling mechanism known as binfmt functionality. This critical flaw manifests when the kernel's memory overcommit feature is enabled, creating a dangerous condition that can be exploited by local attackers to trigger kernel oops errors and subsequently cause system denial of service. The issue specifically targets the processing of malformed a.out binary files, which are a legacy binary format commonly used in unix-like systems. When the kernel attempts to load these malformed binaries while memory overcommit is active, it encounters a condition that leads to an unhandled exception in kernel space, resulting in system instability and potential complete system crash.
The technical root cause of this vulnerability stems from inadequate input validation within the kernel's binary loading subsystem. The binfmt mechanism is responsible for recognizing and executing different binary formats, but when processing malformed a.out binaries under memory overcommit conditions, the kernel fails to properly validate memory allocation requests and handle edge cases in the binary parsing process. This weakness creates a path where a local user can craft a specially designed binary file that, when executed, causes the kernel to access invalid memory locations or perform operations that result in kernel oops. The vulnerability is particularly dangerous because it operates at kernel level, bypassing normal user-space protections and security mechanisms that typically prevent such exploits from succeeding.
From an operational perspective, this vulnerability presents a significant risk to system availability and stability. Local users who can execute code on a target system can leverage this flaw to cause denial of service conditions that may require system reboot to resolve. The impact extends beyond simple service interruption as kernel oops can potentially lead to data loss, system corruption, or even provide a foothold for more sophisticated attacks. The vulnerability affects systems where memory overcommit is enabled, which is often the default configuration in many Linux distributions, making it particularly widespread. Attackers can exploit this condition to repeatedly crash system services or the entire kernel, effectively rendering the system unusable until manual intervention occurs.
The mitigation strategies for CVE-2004-1074 focus on both immediate system hardening and long-term kernel security improvements. System administrators should consider disabling memory overcommit functionality if the system does not require it, as this directly eliminates the vulnerable condition. Additionally, applying kernel patches that properly validate binary format structures and implement robust error handling during memory allocation can resolve the underlying issue. Organizations should also implement monitoring solutions to detect kernel oops events and ensure proper system logging is enabled for forensic analysis. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and relates to ATT&CK technique T1499.004 for network denial of service, though it operates as a local privilege escalation vector rather than a network-based attack. The flaw demonstrates the critical importance of proper input validation and memory management in kernel space, as highlighted by the broader category of kernel-level vulnerabilities that can lead to complete system compromise.