CVE-2008-5856 in ClaSS
Summary
by MITRE
Directory traversal vulnerability in scripts/export.php in ClaSS before 0.8.61 allows remote attackers to read arbitrary files via directory traversal sequences in the ftype parameter.
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Analysis
by VulDB Data Team • 04/29/2025
The vulnerability identified as CVE-2008-5856 represents a critical directory traversal flaw within the ClaSS content management system prior to version 0.8.61. This vulnerability exists in the scripts/export.php file and specifically affects the handling of the ftype parameter, which processes user-supplied input without adequate validation or sanitization. The flaw enables remote attackers to manipulate file access paths through carefully crafted directory traversal sequences, potentially allowing unauthorized access to sensitive system files and data.
This directory traversal vulnerability maps directly 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 operates by exploiting the lack of input validation in the export.php script where the ftype parameter is directly used in file operations without proper sanitization. Attackers can construct malicious input sequences such as ../../etc/passwd or ../../../windows/system32/drivers/etc/hosts to navigate outside the intended directory structure and access arbitrary files on the server filesystem.
The operational impact of this vulnerability extends beyond simple file reading capabilities and represents a significant threat to system security and data integrity. Remote attackers can leverage this flaw to access configuration files, database credentials, application source code, and other sensitive information stored on the server. The vulnerability's remote exploitability means that attackers do not require local system access or authentication to exploit the flaw, making it particularly dangerous in web-facing environments. This type of vulnerability can lead to complete system compromise when combined with other attack vectors or when sensitive files containing database credentials or application secrets are accessed.
From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1083, which describes the discovery of system information through directory traversal attacks. The vulnerability also relates to T1566, representing a method of initial access through web application vulnerabilities. Security practitioners should note that this vulnerability demonstrates the critical importance of input validation and the principle of least privilege in web application development. The flaw exemplifies how simple parameter handling can create severe security implications when proper validation mechanisms are absent from the application code.
Mitigation strategies for CVE-2008-5856 should include immediate patching of the ClaSS application to version 0.8.61 or later, where the directory traversal vulnerability has been addressed through proper input validation. Organizations should implement comprehensive input sanitization measures that filter or reject directory traversal sequences such as ../, ..\, and similar patterns from all user-supplied parameters. Additionally, the principle of least privilege should be enforced by restricting file access permissions and ensuring that the web application operates with minimal required privileges. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, though they should not replace proper application-level fixes. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other application components, particularly in file handling and parameter processing functions.