CVE-2006-4674 in DokuWiki
Summary
by MITRE
Direct static code injection vulnerability in doku.php in DokuWiki before 2006-030-09c allows remote attackers to execute arbitrary PHP code via the X-FORWARDED-FOR HTTP header, which is stored in config.php.
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Analysis
by VulDB Data Team • 06/25/2019
The vulnerability identified as CVE-2006-4674 represents a critical direct static code injection flaw within DokuWiki's doku.php script prior to version 2006-030-09c. This vulnerability resides in the handling of HTTP headers, specifically the X-FORWARDED-FOR header, which is commonly used to identify the original IP address of a client connecting to a web server through an HTTP proxy or load balancer. The flaw occurs when the application fails to properly sanitize or validate input from this header before incorporating it into the configuration file, creating a pathway for remote code execution attacks.
The technical mechanism of this vulnerability involves the improper processing of the X-FORWARDED-FOR header value, which is directly written to the config.php file without adequate sanitization measures. When an attacker crafts a malicious X-FORWARDED-FOR header containing PHP code, this code gets stored in the configuration file and subsequently executed when the application processes the configuration during normal operation. This represents a classic code injection vulnerability that operates at the configuration persistence layer, making it particularly dangerous as it can persist across application restarts and potentially allow attackers to establish long-term access to the system.
From an operational impact perspective, this vulnerability enables remote attackers to execute arbitrary PHP code on the target server with the privileges of the web application user. The attack vector is particularly concerning because it requires no authentication and can be executed through standard HTTP requests, making it highly accessible to attackers. The stored code injection means that even if the initial attack occurs during a single request, the malicious code persists in the configuration file and will be executed every time the application loads its configuration, potentially providing attackers with continuous access to the compromised system. This vulnerability aligns with CWE-94, which describes improper control of generation of code, and represents a specific instance of code injection that occurs through configuration file manipulation rather than direct input processing.
The security implications extend beyond simple code execution to include potential privilege escalation and system compromise. Attackers could leverage this vulnerability to establish backdoors, exfiltrate data, or use the compromised server as a launch point for further attacks within the network infrastructure. The vulnerability demonstrates a fundamental flaw in input validation and output encoding practices, particularly in how applications handle HTTP headers that are intended for logging or proxy information purposes. This flaw violates the principle of least privilege and demonstrates poor separation between user input and system configuration components. Mitigation strategies should focus on immediate patching to the affected DokuWiki versions, implementation of proper input validation for HTTP headers, and removal of unnecessary header processing that could lead to configuration file manipulation. Additionally, organizations should consider implementing web application firewalls and monitoring for unusual header patterns that might indicate exploitation attempts, following ATT&CK technique T1059.007 for execution through PHP code injection and T1566 for the initial access vector through web application vulnerabilities. The vulnerability also highlights the importance of secure configuration management practices and regular security assessments of web applications to identify similar persistence mechanisms that could be exploited for unauthorized code execution.