Source: cve@mitre.org
Directory traversal vulnerability in osTicket 1.6 allows remote attackers to read arbitrary files via a .. (dot dot) in the file parameter to module.php, a different vector than CVE-2005-1439. NOTE: this issue has been disputed by a reliable third party
osTicket 1.6 is vulnerable to a directory traversal attack, allowing attackers to read sensitive files on the server. This vulnerability, exploitable through the module.php file, could lead to data breaches and system compromise by enabling unauthorized access to critical information.
Step 1: Craft Malicious Request: The attacker constructs a URL targeting module.php with a specially crafted file parameter.
Step 2: Directory Traversal: The file parameter contains ../ sequences to navigate up the directory tree.
Step 3: File Access: The server, due to insufficient input validation, processes the malicious file parameter and attempts to access the specified file.
Step 4: Information Disclosure: The server reads the contents of the targeted file and returns it to the attacker, leading to information disclosure.
The vulnerability stems from insufficient input validation in module.php when handling the file parameter. Specifically, the code fails to properly sanitize or restrict the use of .. (dot dot) sequences in the filename provided. This allows an attacker to craft a malicious request containing ../ sequences, effectively traversing the directory structure and accessing files outside the intended scope. The lack of proper path normalization or input validation allows the attacker to bypass security measures and read arbitrary files on the server. The root cause is a missing or inadequate check on the user-supplied filename, leading to a path traversal vulnerability.
While no specific APTs are directly linked to this CVE, the nature of the vulnerability makes it attractive to various threat actors seeking initial access or data exfiltration. The CISA KEV status is not applicable as this CVE is not listed.
Monitor web server access logs for suspicious requests to module.php containing ../ sequences in the file parameter.
Implement file integrity monitoring to detect unauthorized changes to critical system files.
Analyze network traffic for unusual HTTP requests targeting module.php with large file downloads or requests for sensitive file types (e.g., .conf, .log, .db).
Use a Web Application Firewall (WAF) to block requests containing directory traversal patterns.
Upgrade to a patched version of osTicket that addresses the vulnerability. If upgrading is not immediately possible, apply any available security patches or hotfixes.
Implement robust input validation in module.php to sanitize the file parameter. This should include: path normalization, blacklisting of ../ sequences, and whitelisting of allowed file extensions and directories.
Restrict file access permissions to the minimum necessary for the application to function. Ensure that the web server user does not have excessive privileges.
Use a Web Application Firewall (WAF) to filter malicious requests.
Regularly audit the application code for similar vulnerabilities.