CVE-2009-1960 in DokuWiki
Summary
by MITRE
inc/init.php in DokuWiki 2009-02-14, rc2009-02-06, and rc2009-01-30, when register_globals is enabled, allows remote attackers to include and execute arbitrary local files via the config_cascade[main][default][] parameter to doku.php. NOTE: PHP remote file inclusion is also possible in PHP 5 using ftp:// URLs.
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Analysis
by VulDB Data Team • 11/30/2024
The vulnerability described in CVE-2009-1960 represents a critical local file inclusion flaw within DokuWiki versions up to 2009-02-14, rc2009-02-06, and rc2009-01-30. This issue specifically targets the inc/init.php file which processes the config_cascade[main][default][] parameter through doku.php, creating a pathway for remote attackers to execute arbitrary local code. The vulnerability is particularly dangerous when PHP's register_globals directive is enabled, as this configuration setting allows variables from external sources to be automatically imported into the global scope, effectively bypassing normal input validation mechanisms. The flaw operates through parameter manipulation where attackers can inject malicious file paths into the config_cascade parameter, leading to unauthorized code execution on the target server. This vulnerability directly maps to CWE-88, which describes improper neutralization of special elements used in an input vector, and more specifically to CWE-94, which covers the execution of arbitrary code or commands. The operational impact extends beyond simple code execution to include complete system compromise, as attackers can leverage this vulnerability to establish persistent access, escalate privileges, or extract sensitive data from the affected server. The ATT&CK framework categorizes this as a technique involving 'Command and Scripting Interpreter' and 'Exploitation for Client Execution' where adversaries exploit weaknesses in input handling to gain unauthorized access to systems.
The technical exploitation of this vulnerability requires an attacker to craft malicious requests that manipulate the config_cascade[main][default][] parameter in doku.php to point to local files on the target system. When register_globals is enabled, the application fails to properly validate or sanitize this input parameter, allowing the attacker to include files from locations such as /etc/passwd or other system files, or even to include PHP files that may have been uploaded by the attacker. The inclusion of remote files via ftp:// URLs represents an additional attack vector that demonstrates the breadth of the vulnerability, as it shows that the flaw exists not only in local file inclusion but also in remote file inclusion scenarios within PHP 5 environments. This dual nature of the vulnerability significantly increases the attack surface and potential impact. The vulnerability exists because DokuWiki fails to implement proper input sanitization and validation mechanisms for parameters that are directly used in include or require statements within the application's code. The flaw represents a classic case of insufficient input validation and improper privilege management in web applications, where user-provided data is directly processed without adequate security checks. Security researchers have noted that this vulnerability is particularly dangerous because it can be exploited without requiring authentication, making it a prime target for automated exploitation tools and mass scanning attacks.
Mitigation strategies for CVE-2009-1960 focus on both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities. The most effective immediate fix involves disabling the register_globals directive in the PHP configuration, which eliminates the core condition that enables this attack vector. Additionally, administrators should upgrade to patched versions of DokuWiki where the vulnerability has been addressed through proper input validation and sanitization of user-supplied parameters. The application should implement strict input validation that ensures all parameters passed to include or require functions are properly sanitized and validated against a whitelist of acceptable values. Organizations should also consider implementing web application firewalls that can detect and block suspicious parameter manipulation attempts, particularly those targeting known vulnerable parameters. Security hardening measures include disabling remote file inclusion capabilities in PHP, implementing proper access controls, and establishing robust logging mechanisms to detect potential exploitation attempts. The principle of least privilege should be enforced by ensuring that the web application runs with minimal required permissions and that file inclusion operations are restricted to predefined, trusted directories. Regular security audits and code reviews should be conducted to identify similar input validation weaknesses in other parts of the application, as this vulnerability represents a common pattern in web application security flaws that can be found in many legacy systems. Organizations should also implement network segmentation and monitoring to detect unauthorized access attempts and potential exploitation of similar vulnerabilities in their infrastructure.