CVE-2025-13771: Uniong WebITR Path Traversal Vulnerability

CVE-2025-13771 Overview

CVE-2025-13771 is an arbitrary file read vulnerability in Uniong WebITR, a web-based attendance and time tracking application. The flaw allows authenticated remote attackers to abuse a relative path traversal weakness [CWE-23] to download arbitrary files from the underlying operating system. Attackers only need low-privileged application credentials to reach the vulnerable download function over the network. Successful exploitation exposes application source code, configuration files, credentials, and other sensitive host data.

Critical Impact
Authenticated attackers can read arbitrary files from the WebITR server, including configuration files and credentials, enabling further compromise of the application and connected systems.

Affected Products

Uniong WebITR (all versions prior to the vendor fix)
Deployments exposing the WebITR web interface to authenticated users
Environments where WebITR credentials are broadly issued to employees

Discovery Timeline

2025-11-28 - CVE-2025-13771 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2025-13771

Vulnerability Analysis

The vulnerability resides in a WebITR file handling endpoint that accepts a user-supplied file path or file name. The application fails to normalize and validate the requested path before reading the file from disk. An authenticated attacker can inject relative path traversal sequences such as ../ to escape the intended directory and reach files outside the application root.

Because the read operation is performed with the privileges of the WebITR service account, any file the service can access becomes readable to the attacker. This typically includes application configuration, database connection strings, session data, and system files readable by the service user. The Common Weakness Enumeration classifies this issue as [CWE-23] Relative Path Traversal.

Root Cause

The root cause is missing or insufficient input sanitization on a file path parameter used in a download or view function. WebITR does not canonicalize the path, restrict access to an allowlisted directory, or reject traversal sequences before invoking the file read. This design choice trusts authenticated users to supply well-formed paths.

Attack Vector

Exploitation requires network access to the WebITR web interface and a valid low-privileged account. The attacker submits a crafted request to the vulnerable endpoint containing a traversal payload such as ..%2f..%2fetc%2fpasswd or a Windows equivalent like ..\..\Windows\win.ini. The server resolves the path relative to the application directory and returns the file contents in the HTTP response. No user interaction is required beyond the attacker's own authenticated session.

No public proof-of-concept code is available at this time. For technical specifics, refer to the TWCERT Security Advisory #10539 and TWCERT Security Advisory #10538.

Detection Methods for CVE-2025-13771

Indicators of Compromise

HTTP requests to WebITR endpoints containing ../, ..\, %2e%2e%2f, or %2e%2e%5c sequences in query strings or POST bodies
Successful 200 OK responses to file download requests referencing paths outside the WebITR application directory
WebITR access logs showing authenticated sessions retrieving unusually large or unexpected file types such as .conf, .ini, .env, or passwd
Repeated file access errors followed by successful reads from a single account, indicating path enumeration

Detection Strategies

Deploy web application firewall (WAF) rules that identify and block path traversal encodings in requests targeting WebITR download and view handlers
Correlate authenticated WebITR session activity with abnormal file access patterns using centralized log analysis
Baseline normal WebITR file request paths and alert on deviations that reference system directories

Monitoring Recommendations

Forward WebITR application and web server logs to a security information and event management (SIEM) platform for continuous analysis
Monitor authentication logs for compromised or brute-forced WebITR accounts that could be leveraged for exploitation
Track outbound data volume from the WebITR server to detect bulk exfiltration following successful file reads

How to Mitigate CVE-2025-13771

Immediate Actions Required

Apply the vendor-supplied WebITR patch referenced in the TWCERT advisories as soon as it is available
Restrict WebITR access to trusted networks using firewall rules or a VPN until patching is complete
Review and rotate any credentials, API keys, or secrets stored in files accessible to the WebITR service account
Audit WebITR user accounts and disable inactive or unnecessary accounts to reduce the pool of usable attacker credentials

Patch Information

Uniong has coordinated disclosure through the Taiwan Computer Emergency Response Team (TWCERT). Administrators should consult the TWCERT Security Advisory #10539 and TWCERT Security Advisory #10538 for the fixed version and upgrade procedure. Contact Uniong directly if the fixed release is not accessible through normal update channels.

Workarounds

Place WebITR behind a reverse proxy or WAF that inspects and blocks path traversal payloads in request parameters
Enforce strict file system permissions so the WebITR service account cannot read sensitive OS files or credential stores
Enable multi-factor authentication on WebITR accounts to raise the cost of acquiring the authenticated access required for exploitation

bash

# Example ModSecurity rule to block path traversal against WebITR endpoints
SecRule REQUEST_URI|ARGS "@rx (\.\./|\.\.\\|%2e%2e%2f|%2e%2e%5c)" \
  "id:1013771,phase:2,deny,status:403,log,\
   msg:'CVE-2025-13771 WebITR path traversal attempt'"