CVE-2006-0795 in Quirex
Summary
by MITRE
Absolute path traversal vulnerability in convert.cgi in Quirex 2.0.2 and earlier allows remote attackers to read arbitrary files, and possibly execute arbitrary code, via the (1) quiz_head, (2) quiz_foot, and (3) template variables.
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Analysis
by VulDB Data Team • 07/19/2018
The CVE-2006-0795 vulnerability represents a critical absolute path traversal flaw in the convert.cgi script of Quirex 2.0.2 and earlier versions, fundamentally compromising the security posture of affected systems. This vulnerability resides within the web application's file handling mechanisms, specifically targeting the quiz_head, quiz_foot, and template variables that are processed through the convert.cgi interface. The flaw allows remote attackers to manipulate these parameters to access arbitrary files on the server filesystem, potentially leading to unauthorized data access, system compromise, and execution of malicious code.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the convert.cgi script. When users provide values for the quiz_head, quiz_foot, or template variables, the application fails to properly validate or sanitize these inputs before using them in file system operations. Attackers can exploit this by crafting malicious input that includes directory traversal sequences such as ../ or ..\, enabling them to navigate beyond the intended directories and access sensitive files that should remain protected. This represents a classic case of improper input validation and insufficient access controls, aligning with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
The operational impact of this vulnerability extends beyond simple file access, potentially enabling full system compromise through code execution capabilities. Remote attackers can leverage this vulnerability to read system configuration files, database credentials, user authentication data, and other sensitive information stored on the server. In some configurations, the vulnerability may also permit arbitrary code execution, allowing attackers to establish persistent access, install backdoors, or conduct further reconnaissance against the network. The implications are particularly severe for web applications handling sensitive data, as this vulnerability can lead to complete system compromise and data breaches.
Mitigation strategies for CVE-2006-0795 require immediate attention through multiple defensive layers. The primary remediation involves upgrading to a patched version of Quirex beyond 2.0.2, as this vulnerability was addressed in subsequent releases. Additionally, implementing proper input validation and sanitization measures within the convert.cgi script is essential, including the use of allowlists for valid input parameters and strict validation of all user-supplied data. System administrators should also consider implementing web application firewalls to detect and block malicious path traversal attempts, while applying the principle of least privilege to limit file system access for the web application. Organizations should conduct comprehensive security assessments to identify similar vulnerabilities in other applications and establish robust input validation frameworks to prevent similar issues, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1566.001 for spearphishing attachments. The vulnerability underscores the importance of secure coding practices and proper input validation in preventing remote code execution and privilege escalation attacks.