CVE-2006-0331 in Change passwd
Summary
by MITRE
Buffer overflow in Change passwd 3.1 (chpasswd) SquirrelMail plugin allows local users to execute arbitrary code via long command line arguments.
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Analysis
by VulDB Data Team • 02/03/2025
The vulnerability identified as CVE-2006-0331 represents a critical buffer overflow flaw within the Change passwd 3.1 SquirrelMail plugin, a widely used email client component in web-based email systems. This issue affects the chpasswd utility functionality that allows users to modify their passwords through the SquirrelMail interface, creating a dangerous attack vector for local adversaries who can exploit this weakness to gain unauthorized system access. The vulnerability specifically manifests when the plugin processes command line arguments, failing to properly validate input length and causing memory corruption that can be leveraged for code execution.
The technical implementation of this buffer overflow stems from inadequate input validation within the chpasswd plugin's argument processing mechanism. When local users provide excessively long command line arguments to the vulnerable plugin, the system fails to enforce proper bounds checking on buffer allocations, resulting in memory overwrite conditions that can be exploited to execute arbitrary code with elevated privileges. This flaw aligns with CWE-121, which categorizes buffer overflow vulnerabilities occurring when insufficient space is allocated for data, and specifically relates to CWE-787, which addresses out-of-bounds writes in buffer operations. The vulnerability demonstrates characteristics of a classic stack-based buffer overflow, where attacker-controlled data overflows into adjacent memory locations, potentially allowing modification of critical program execution flow.
From an operational impact perspective, this vulnerability creates severe security implications for systems running vulnerable SquirrelMail installations, as local users can escalate privileges and execute malicious code without requiring authentication. The attack surface is particularly concerning because it operates at the local user level, meaning that any user with access to the system can potentially exploit this weakness to gain root or administrative privileges. This type of vulnerability directly maps to ATT&CK technique T1068, which involves the exploitation of local system privileges to gain elevated access, and T1059, which covers the execution of commands through system interfaces. The vulnerability essentially provides a path for privilege escalation that bypasses normal authentication mechanisms, making it particularly dangerous in multi-user environments where local access is not restricted.
Mitigation strategies for this vulnerability should prioritize immediate patching of the affected SquirrelMail plugin to address the buffer overflow in the chpasswd functionality. System administrators must ensure that all SquirrelMail installations are updated to versions that properly validate command line argument lengths and implement proper input sanitization techniques. Additionally, implementing input length restrictions and boundary checking mechanisms within the plugin's argument processing code will prevent the overflow condition from occurring. Security monitoring should include detection of unusual command line argument patterns that might indicate exploitation attempts, while network segmentation and access controls should limit local user privileges where possible. The remediation efforts should also consider implementing principle of least privilege models and regular security audits to identify similar vulnerabilities in other system components that might present analogous buffer overflow risks.