CVE-2008-4626 in yappa-ng
Summary
by MITRE
Directory traversal vulnerability in index.php in Fritz Berger yet another php photo album - next generation (yappa-ng) 2.3.2 and possibly other versions through 2.3.3-beta0, when magic_quotes_gpc is disabled, allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the album parameter.
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Analysis
by VulDB Data Team • 11/08/2024
The vulnerability identified as CVE-2008-4626 represents a critical directory traversal flaw within the yappa-ng photo album application version 2.3.2 and potentially affecting versions up to 2.3.3-beta0. This vulnerability specifically targets the index.php script where user input is processed without adequate sanitization mechanisms. The flaw occurs when the magic_quotes_gpc directive is disabled on the web server, creating an environment where malicious input can be directly interpreted by the application. The vulnerability manifests through the album parameter which accepts user-supplied input containing directory traversal sequences using the .. (dot dot) notation. When this parameter is processed, the application fails to properly validate or sanitize the input, allowing attackers to navigate the file system beyond the intended directories.
The technical exploitation of this vulnerability follows a pattern consistent with CWE-22 directory traversal attacks where attacker-controlled input is used to manipulate file access operations. The application's failure to implement proper input validation creates a path traversal condition that can be leveraged to include arbitrary local files. This weakness directly maps to the ATT&CK technique T1505.003 for server-side include attacks and T1059.007 for command execution through file inclusion. When an attacker crafts a malicious request containing .. sequences in the album parameter, the application processes these paths without proper restriction, potentially allowing access to sensitive files such as configuration files, database credentials, or system files. The vulnerability becomes particularly dangerous in environments where the web application has elevated privileges or where sensitive data is stored in predictable locations.
The operational impact of this vulnerability extends beyond simple information disclosure to potential remote code execution capabilities. Attackers can leverage this flaw to execute arbitrary code on the affected server by including and executing local files that contain malicious payloads. This includes the possibility of accessing php.ini files, database configuration files, or even system files that may contain sensitive credentials or configuration details. The vulnerability affects not just the display of photos but can potentially compromise the entire web server infrastructure. Organizations running yappa-ng versions 2.3.2 through 2.3.3-beta0 without proper input validation or with magic_quotes_gpc disabled face significant risk of unauthorized access to their systems and data. The attack vector requires no special privileges and can be executed through standard web browser interactions, making it particularly dangerous for public-facing web applications.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and sanitization mechanisms. The primary defense involves ensuring that all user-supplied input is properly validated before processing, specifically rejecting any input containing directory traversal sequences such as .. or %2e%2e. Implementing proper path normalization and restricting file access to predetermined directories can prevent attackers from accessing arbitrary files. Organizations should also ensure that magic_quotes_gpc is enabled or implement alternative input sanitization measures. The recommended approach includes using allowlist validation for the album parameter, restricting file access to specific directories, and implementing proper error handling that does not reveal system file paths. Additionally, deploying web application firewalls and implementing security headers can provide additional protection layers. Regular security updates and patches should be applied to ensure that known vulnerabilities are addressed, and application developers should follow secure coding practices to prevent similar issues in future releases. The vulnerability demonstrates the critical importance of input validation and proper file access controls in preventing directory traversal attacks.