CVE-2005-3392 in PHP
Summary
by MITRE
Unspecified vulnerability in PHP before 4.4.1, when using the virtual function on Apache 2, allows remote attackers to bypass safe_mode and open_basedir directives.
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Analysis
by VulDB Data Team • 06/12/2019
This vulnerability resides in the php web application scripting language version 4.4.0 and earlier, specifically affecting systems running on apache 2 web server with the virtual function enabled. The issue represents a critical security flaw that undermines fundamental web application security mechanisms designed to restrict file access and prevent unauthorized operations. The vulnerability allows remote attackers to circumvent the safe_mode and open_basedir directives that are essential components of php's security model for controlling file access permissions.
The technical flaw manifests through improper handling of the virtual function within apache 2 environment where php operates. When php processes requests through apache 2, the virtual function fails to properly validate or enforce the security restrictions imposed by safe_mode and open_basedir configurations. This creates an exploitable condition where malicious actors can manipulate the execution flow to access files and directories that should normally be restricted. The vulnerability stems from inadequate boundary checking and access control enforcement within the php interpreter's interaction with apache 2's virtual hosting capabilities.
The operational impact of this vulnerability is severe as it provides attackers with unauthorized access to the underlying file system beyond what the administrator intended to permit. Safe_mode and open_basedir are fundamental security features designed to prevent php applications from accessing files outside their designated directories, particularly critical for shared hosting environments where multiple applications operate on the same server. When these protections are bypassed, attackers can potentially read sensitive files, execute arbitrary code, or gain access to database credentials and other confidential information stored on the server. This vulnerability directly violates the principle of least privilege and can lead to complete system compromise.
The vulnerability maps to CWE-284 Access Control Issues and aligns with ATT&CK technique T1059 Command and Scripting Interpreter as it enables remote code execution through manipulated file access patterns. Mitigation strategies include upgrading to php version 4.4.1 or later where the vulnerability has been addressed through proper implementation of access control checks. Organizations should also implement additional security measures such as disabling unnecessary php functions, configuring proper file permissions, and monitoring for suspicious file access patterns. Network segmentation and intrusion detection systems can help detect exploitation attempts, while regular security audits should verify that safe_mode and open_basedir configurations are properly enforced. The fix implemented in php 4.4.1 specifically addresses the virtual function handling to ensure proper enforcement of directory restrictions and prevents unauthorized access to restricted file system areas.