CVE-2004-1431 in Formmail.php
Summary
by MITRE
FormMail.php 5.0, and possibly other versions, allows remote attackers to read arbitrary files via a full pathname in the ar_file (auto-reply) parameter.
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Analysis
by VulDB Data Team • 07/15/2017
The vulnerability identified as CVE-2004-1431 affects FormMail.php version 5.0 and potentially other iterations of this web application, presenting a critical security flaw that enables remote attackers to access arbitrary files on the target system. This issue stems from inadequate input validation within the auto-reply file parameter known as ar_file, which fails to properly sanitize user-supplied pathnames before processing. The vulnerability resides in the application's handling of file paths, allowing malicious actors to exploit this weakness by supplying full pathname references that bypass normal file access controls and directory restrictions.
The technical implementation of this vulnerability demonstrates a classic case of improper input validation and inadequate file access controls, which aligns with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory. When an attacker submits a malicious ar_file parameter containing a full pathname, the FormMail.php script processes this input without sufficient validation, resulting in the application attempting to read files from locations outside the intended directory structure. This flaw essentially creates a path traversal condition that allows attackers to access system files, configuration data, or sensitive information that should remain protected within restricted directories.
The operational impact of CVE-2004-1431 extends beyond simple information disclosure, as it provides attackers with the ability to access potentially sensitive system resources including configuration files, database credentials, system logs, and other confidential data that could compromise the entire web application environment. Attackers can leverage this vulnerability to gather intelligence about the target system, potentially leading to further exploitation attempts such as privilege escalation or lateral movement within the network. The vulnerability also presents a risk of data corruption or system instability if attackers can access and modify critical system files through this pathway.
Security professionals should consider this vulnerability in relation to the ATT&CK framework, specifically under the T1083 - File and Directory Discovery tactic, where adversaries seek to identify files and directories on compromised systems. The remediation approach should focus on implementing strict input validation and sanitization for all user-supplied parameters, particularly those related to file operations. Organizations should deploy proper parameter validation mechanisms that reject any input containing absolute path references or directory traversal sequences such as ../ or ..\. Additionally, implementing a whitelist approach for acceptable file paths and ensuring proper file access controls through principle of least privilege configurations will significantly reduce the risk of exploitation. The vulnerability also underscores the importance of regular security assessments and code reviews to identify similar flaws in web applications that may be susceptible to path traversal attacks and other input validation vulnerabilities.