CVE-2009-3149 in Elgg
Summary
by MITRE
Directory traversal vulnerability in _css/js.php in Elgg 1.5, when magic_quotes_gpc is disabled, allows remote attackers to read arbitrary files via a .. (dot dot) in the js parameter. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 12/08/2024
The vulnerability identified as CVE-2009-3149 represents a critical directory traversal flaw in the Elgg 1.5 content management system that specifically targets the _css/js.php script. This vulnerability exploits a fundamental weakness in input validation mechanisms that fail to properly sanitize user-supplied data, creating an avenue for remote attackers to access arbitrary files on the server. The flaw becomes particularly dangerous when the PHP configuration parameter magic_quotes_gpc is disabled, removing a crucial built-in protection mechanism that would otherwise escape special characters in GET, POST, and COOKIE data.
The technical implementation of this vulnerability stems from improper validation of the js parameter within the _css/js.php file, which processes JavaScript file requests for the Elgg platform. When an attacker crafts a malicious request containing directory traversal sequences such as .. (dot dot) within the js parameter, the application fails to adequately filter or sanitize this input before processing. This allows the attacker to navigate through the file system hierarchy and access files that should remain protected, including sensitive configuration files, database credentials, and potentially system files that could compromise the entire server infrastructure.
From an operational perspective, this vulnerability poses significant risks to organizations utilizing Elgg 1.5 systems, as it enables attackers to perform unauthorized file access without requiring legitimate credentials or authentication. The impact extends beyond simple information disclosure, as attackers could potentially access database configuration files containing sensitive connection strings, user credentials, or application-specific secrets that could facilitate further attacks. The vulnerability operates at the application layer and can be exploited through standard web browser interfaces, making it particularly dangerous as it requires no specialized tools or privileged access beyond basic web browsing capabilities.
The attack vector for this vulnerability aligns with common exploitation patterns documented in the attack framework, specifically relating to path traversal techniques that fall under the MITRE ATT&CK framework's technique T1059.1001 for command and scripting interpreter. This vulnerability directly corresponds to CWE-22, which defines the weakness of improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The vulnerability is further classified under the broader category of insecure input handling, where applications fail to validate or sanitize user inputs before using them in file system operations.
Security mitigations for this vulnerability should focus on immediate patching of the Elgg 1.5 installation to the latest available version that contains the necessary input validation fixes. Organizations should also implement input sanitization measures at the web application level, ensuring that all user-supplied parameters are properly validated and filtered before being processed. Additionally, system administrators should consider implementing web application firewalls that can detect and block suspicious path traversal patterns, and ensure that magic_quotes_gpc is properly configured or that equivalent security measures are implemented at the application level. Regular security audits and code reviews should be conducted to identify similar input validation weaknesses in other components of the application stack.