CVE-2009-2124 in Elvinbts
Summary
by MITRE
Directory traversal vulnerability in page.php in Elvin 1.2.0 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the id parameter.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability identified as CVE-2009-2124 represents a critical directory traversal flaw within the Elvin content management system version 1.2.0. This security weakness resides in the page.php script which fails to properly validate user input before processing file inclusion operations. The vulnerability specifically manifests when the id parameter contains directory traversal sequences such as .. (dot dot) which allows attackers to manipulate the file path resolution mechanism. This flaw falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The technical implementation of this vulnerability exploits the lack of input sanitization in the page.php script where user-supplied data is directly incorporated into file system operations without adequate validation. When an attacker submits a malicious id parameter containing sequences like ../../etc/passwd or similar directory traversal patterns, the application processes these inputs without proper boundary checking, enabling unauthorized access to local files that should normally be restricted. This occurs because the application's file inclusion mechanism does not adequately restrict the paths that can be accessed through user input, allowing attackers to navigate outside the intended directory structure.
The operational impact of this vulnerability extends beyond simple file access, as it can potentially enable remote code execution depending on the system configuration and the files that become accessible through the traversal. Attackers can leverage this weakness to read sensitive system files, configuration data, or application source code that may contain database credentials, encryption keys, or other confidential information. The remote nature of this attack means that an attacker does not require local system access or physical presence, making it particularly dangerous for web applications exposed to the internet. According to the MITRE ATT&CK framework, this vulnerability maps to T1059.007 for Command and Scripting Interpreter and T1566.001 for Pre-Attack, as it provides initial access vectors that can lead to further exploitation and privilege escalation.
Mitigation strategies for CVE-2009-2124 should focus on implementing proper input validation and output encoding mechanisms within the application. The most effective approach involves implementing strict input sanitization that filters or rejects any input containing directory traversal sequences such as .. or %2e%2e. Additionally, developers should employ whitelisting techniques where only predefined, safe values are accepted for the id parameter. The application should also implement proper file access controls and ensure that file inclusion operations are performed within restricted directories. Security best practices recommend using absolute paths for file operations and implementing proper access controls to prevent unauthorized file system access. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for suspicious directory traversal patterns and automatically block such requests. Regular security audits and code reviews should be conducted to identify and remediate similar vulnerabilities in other components of the application stack, as this type of weakness often appears in legacy systems that have not received proper security updates or modernization efforts.