CVE-2011-5210 in Limny
Summary
by MITRE
Directory traversal vulnerability in admin/preview.php in Limny 3.0.0 allows remote attackers to read arbitrary files via a ..%2F (encoded dot dot slash) in the theme parameter.
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Analysis
by VulDB Data Team • 08/17/2017
The vulnerability identified as CVE-2011-5210 represents a critical directory traversal flaw within the Limny 3.0.0 content management system, specifically affecting the admin/preview.php component. This vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly handle maliciously crafted file paths. The flaw manifests when the application processes the theme parameter without adequate restrictions on directory navigation sequences, allowing attackers to manipulate the file system access through encoded traversal sequences.
The technical exploitation of this vulnerability relies on the manipulation of the theme parameter through URL encoding where attackers can inject ..%2F sequences that represent the traditional directory traversal notation. This encoded format bypasses basic input validation checks that might only inspect for literal .. characters, allowing the application to interpret the encoded sequence as a legitimate traversal path. The vulnerability falls under CWE-22 which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw demonstrates a classic lack of proper input sanitization and validation that enables arbitrary file system access.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to access sensitive files within the application's directory structure. Remote attackers can potentially retrieve configuration files, database credentials, application source code, and other sensitive data that may be stored within the web server's file system. This access could lead to complete system compromise, especially if the application has elevated privileges or if sensitive configuration files contain database connection strings, API keys, or other credential information. The vulnerability affects the confidentiality and integrity of the system, as unauthorized access to application files could expose the entire system architecture.
Mitigation strategies for this vulnerability must focus on implementing robust input validation and sanitization measures that properly handle all forms of directory traversal sequences, including encoded variants. Organizations should ensure that all user-supplied input is thoroughly validated against a whitelist of acceptable values, and that any traversal sequences are explicitly rejected. The implementation of proper path normalization and canonicalization techniques can help prevent exploitation by ensuring that all file paths are resolved to their absolute form before processing. Additionally, the principle of least privilege should be enforced by running the application with minimal required permissions, limiting the potential damage from successful exploitation. Security controls should include regular input validation testing, web application firewalls, and proper access controls to prevent unauthorized file access. The vulnerability also highlights the importance of keeping software components updated and implementing comprehensive security testing practices to identify and remediate similar flaws in other applications. This type of vulnerability is commonly categorized under the ATT&CK technique T1083 - File and Directory Discovery, which describes adversary behavior focused on identifying files and directories that may contain sensitive information.