CVE-2008-6592 in LightNEasy
Summary
by MITRE
thumbsup.php in Thumbs-Up 1.12, as used in LightNEasy "no database" (aka flat) and SQLite 1.2.2 and earlier, allows remote attackers to copy, rename, and read arbitrary files via directory traversal sequences in the image parameter with a modified cache_dir parameter containing a %00 (encoded null byte).
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability identified as CVE-2008-6592 represents a critical directory traversal flaw in the Thumbs-Up 1.12 component of LightNEasy content management systems. This vulnerability specifically affects versions where the system operates in "no database" or SQLite modes, creating a significant security risk for web applications that rely on these configurations. The flaw manifests through the thumbsup.php script which processes image parameters without adequate input validation, allowing malicious actors to manipulate file access through carefully crafted directory traversal sequences.
The technical implementation of this vulnerability exploits the improper handling of the cache_dir parameter combined with a modified image parameter containing a null byte encoded as %00. This combination enables attackers to bypass normal file access controls and manipulate the file system operations performed by the application. When the system processes the modified cache_dir parameter, it fails to properly sanitize the input, allowing the null byte to terminate string processing prematurely and effectively circumventing path validation mechanisms. This creates a condition where arbitrary file operations can be executed with the privileges of the web application process.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass full system compromise potential. Attackers can leverage this flaw to read sensitive files including configuration files, user data, and potentially system files that should remain inaccessible. The ability to copy and rename files through this vulnerability means that attackers can not only extract information but also modify the application's behavior by replacing critical files with malicious versions. This represents a severe privilege escalation vector that can lead to complete system takeover when combined with other exploitation techniques.
Mitigation strategies for this vulnerability must address both the immediate input validation issues and the broader architectural concerns that allowed such flaws to exist. Organizations should implement strict input validation routines that properly sanitize all user-supplied parameters, particularly those used in file system operations. The use of whitelisting approaches for file paths and implementing proper path normalization techniques can prevent directory traversal attempts. Additionally, the application should avoid using user-controllable parameters in file system operations without comprehensive validation. This vulnerability aligns with CWE-22, which specifically addresses directory traversal flaws, and represents a clear violation of the principle of least privilege in system design. Security practitioners should also consider implementing web application firewalls to detect and block such exploitation attempts, while ensuring that all web applications are regularly updated to remove known vulnerable components. The ATT&CK framework categorizes this as a file system access technique, specifically under the category of privilege escalation through file manipulation, making it a critical target for defensive security measures.