CVE-2025-31131: Yeswiki Path Traversal Vulnerability

CVE-2025-31131 Overview

CVE-2025-31131 is a path traversal vulnerability affecting YesWiki, a wiki system written in PHP. The squelette parameter is vulnerable to path traversal attacks, enabling attackers to read arbitrary files on the server. This vulnerability allows unauthenticated remote attackers to access sensitive configuration files, credentials, and other protected data by manipulating file path inputs.

Critical Impact

Unauthenticated attackers can read arbitrary files on the server, potentially exposing sensitive configuration data, credentials, and system information.

Affected Products

• YesWiki versions prior to 4.5.2

Discovery Timeline

• April 1, 2025 - CVE-2025-31131 published to NVD
• May 9, 2025 - Last updated in NVD database

Technical Details for CVE-2025-31131

Vulnerability Analysis

This path traversal vulnerability (CWE-22) exists in YesWiki's handling of the squelette parameter. Path traversal attacks, also known as directory traversal, allow attackers to escape the intended directory structure by using special character sequences like ../ to navigate the file system. In this case, insufficient validation of the squelette parameter permits attackers to construct malicious requests that traverse outside the web application's root directory and access arbitrary files on the server.

The vulnerability is particularly concerning because it requires no authentication and can be exploited remotely over the network. Successful exploitation grants read access to sensitive files, which could include configuration files containing database credentials, API keys, or other secrets that could facilitate further attacks against the system.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization of the squelette parameter. The application fails to adequately filter or neutralize path traversal sequences before using the parameter value in file system operations. This allows malicious input containing directory traversal characters to be processed, enabling access to files outside the intended directory scope.

Attack Vector

This vulnerability is exploitable over the network without requiring any authentication or user interaction. An attacker can craft malicious HTTP requests containing path traversal sequences in the squelette parameter to access arbitrary files on the web server. Common targets include:

• /etc/passwd for user enumeration on Linux systems
• Configuration files containing database credentials
• Application source code and sensitive business logic
• Log files that may contain sensitive information

The exploitation technique involves injecting sequences such as ../ repeatedly to traverse up the directory tree from the current working directory to reach target files elsewhere on the file system.

Detection Methods for CVE-2025-31131

Indicators of Compromise

• HTTP requests containing path traversal sequences (../, ..%2f, %2e%2e/) in the squelette parameter
• Unusual file access patterns in web server logs showing attempts to read system files
• Access to sensitive files such as /etc/passwd, configuration files, or other non-web content through the web application

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block path traversal patterns in request parameters
• Monitor web server access logs for requests containing encoded or decoded directory traversal sequences
• Deploy intrusion detection systems (IDS) with signatures for path traversal attack patterns
• Review application logs for file access errors or attempts to access files outside the web root

Monitoring Recommendations

• Enable detailed logging for the YesWiki application to capture all parameter values in requests
• Set up alerts for any access attempts targeting system files through web requests
• Monitor for unusual patterns of file read operations originating from the web server process
• Implement file integrity monitoring on sensitive configuration files

How to Mitigate CVE-2025-31131

Immediate Actions Required

• Upgrade YesWiki to version 4.5.2 or later immediately
• Review web server logs for signs of exploitation attempts
• Implement WAF rules to block path traversal patterns as a defense-in-depth measure
• Audit any potentially exposed sensitive files for unauthorized access

Patch Information

YesWiki has released version 4.5.2 which addresses this vulnerability. The fix is available in commit f78c915369a60c74ab8f38561ae93a4aaca9b989. Organizations should upgrade to the patched version as soon as possible. For detailed information about the vulnerability and the fix, refer to the GitHub Security Advisory and the patch commit.

Workarounds

• Implement web application firewall rules to filter requests containing path traversal sequences in the squelette parameter
• Restrict file system permissions to limit the web server's read access to only necessary directories
• Consider placing the YesWiki application behind a reverse proxy with additional input validation
• If upgrading is not immediately possible, disable or restrict access to functionality using the squelette parameter until the patch can be applied