CVE-2004-1058 in Linux
Summary
by MITRE
Race condition in Linux kernel 2.6 allows local users to read the environment variables of another process that is still spawning via /proc/.../cmdline.
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Analysis
by VulDB Data Team • 06/30/2019
The vulnerability described in CVE-2004-1058 represents a critical race condition within the Linux kernel version 2.6 that fundamentally undermines process isolation and information security principles. This flaw exists in the handling of process information within the /proc filesystem, specifically affecting how the kernel manages the cmdline interface for processes that are in the transitional state of spawning. The race condition occurs during the brief window between when a process begins execution and when its environment variables become fully accessible through the /proc filesystem interface, creating a temporal vulnerability that can be exploited by local malicious users.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within the kernel's process management subsystem. When a new process is created, the kernel must populate various /proc entries including the cmdline file that typically contains the command line arguments and environment variables of the process. However, due to inadequate locking mechanisms during this initialization phase, a local attacker can exploit the timing gap to access another process's environment variables before they are properly sanitized or made available. This race condition specifically affects the /proc/PID/cmdline interface where PID represents the process identifier of the target process, and the timing window can be manipulated through careful process creation and access patterns.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable sophisticated attacks that leverage process environment information for privilege escalation or further exploitation. Attackers can use the leaked environment variables to discover sensitive information such as database passwords, API keys, or other credential material that may be passed as environment variables to applications. The vulnerability particularly affects systems where applications rely on environment variables for configuration and authentication, making it a valuable vector for attackers seeking to gather intelligence about running processes. According to CWE-362, this represents a classic race condition vulnerability that can lead to security flaws through improper synchronization, while the ATT&CK framework would categorize this under privilege escalation techniques through process manipulation and information gathering.
Mitigation strategies for CVE-2004-1058 require both immediate kernel updates and careful system administration practices to address the underlying race condition. The most effective solution involves applying the appropriate kernel security patches that implement proper locking mechanisms around process initialization and /proc filesystem access. System administrators should also consider implementing process monitoring and access control measures that limit the ability of local users to enumerate processes and access sensitive information. Additional mitigations include disabling unnecessary access to /proc filesystem entries, implementing proper user privilege separation, and conducting regular security audits to identify processes that may be vulnerable to this type of information disclosure attack. The vulnerability highlights the importance of proper synchronization in kernel code and demonstrates how seemingly minor timing issues can create significant security implications in operating system internals.