CVE-2025-13768: Uniong WebITR Auth Bypass Vulnerability

CVE-2025-13768 Overview

CVE-2025-13768 is an authentication bypass vulnerability in WebITR, a time and attendance management application developed by Uniong. The flaw allows an authenticated remote attacker to log into the system as any user by modifying a specific parameter in a request. Exploitation requires the attacker to first obtain a target user ID, after which they can impersonate that account. The vulnerability is classified under [CWE-639: Authorization Bypass Through User-Controlled Key], a category commonly referred to as Insecure Direct Object Reference (IDOR) affecting authentication logic.

Critical Impact
An authenticated attacker can fully impersonate any user, including administrators, breaking the confidentiality and integrity guarantees of the WebITR application.

Affected Products

Uniong WebITR (all versions identified in the TWCERT advisory)
Web-based time and attendance deployments using WebITR
Enterprise environments integrating WebITR for workforce management

Discovery Timeline

2025-11-28 - CVE-2025-13768 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-13768

Vulnerability Analysis

The vulnerability resides in the authentication workflow of WebITR. After a low-privileged user authenticates, a specific parameter in a subsequent request controls which user identity is assumed by the server. The application accepts the client-supplied identifier without verifying that the authenticated session is authorized to act on behalf of the referenced user. By substituting the target user ID, an attacker logs in as that user.

The weakness aligns with [CWE-639], where access control decisions rely on a user-controlled key. The application trusts the parameter as if it were validated server-side. Because WebITR holds attendance records, payroll-relevant data, and administrative configuration, account takeover yields direct access to sensitive personnel information. Successful exploitation requires network access to the WebITR interface and a valid low-privilege account, conditions easily satisfied in deployments exposed to corporate intranets or the internet.

Root Cause

The root cause is missing authorization enforcement on a parameter that selects the authenticated identity. The server treats the parameter as authoritative rather than cross-checking it against the established session context. No server-side validation ties the requested user ID to the credentials presented during login.

Attack Vector

The attack vector is network-based and requires prior authentication with any valid account. An attacker enumerates or obtains a target user ID through directory listings, email patterns, exposed reports, or social engineering. The attacker then issues a request to the affected endpoint while substituting the target user ID in the vulnerable parameter. The application returns a session bound to the impersonated account, granting access equivalent to that user's role.

No verified proof-of-concept code is publicly available. Refer to the TWCERT Security Advisory for vendor-coordinated details.

Detection Methods for CVE-2025-13768

Indicators of Compromise

Authentication events where the session user identifier changes mid-session or does not match the credentials used at login
Successive logins from the same source IP impersonating multiple distinct user IDs within a short window
Access to administrative WebITR endpoints originating from accounts that historically only access self-service functions
Unexpected modifications to attendance records, leave balances, or user roles initiated by atypical accounts

Detection Strategies

Inspect WebITR application logs for requests where the user ID parameter differs from the authenticated session principal
Correlate login events against subsequent API calls to identify mismatches between authenticated identity and acting identity
Deploy web application firewall (WAF) rules that flag parameter tampering on authentication-related endpoints
Hunt for anomalous role transitions or session escalations across the WebITR audit trail

Monitoring Recommendations

Forward WebITR authentication and audit logs to a centralized SIEM for correlation against user behavior baselines
Alert on any successful login event followed by privileged actions inconsistent with the user's role
Monitor outbound data access volumes per WebITR account to identify mass record retrieval consistent with account takeover

How to Mitigate CVE-2025-13768

Immediate Actions Required

Restrict network exposure of WebITR to trusted internal segments or VPN-protected access until a patch is applied
Audit existing WebITR accounts and revoke unused or stale credentials that could serve as a foothold
Review recent authentication logs for evidence of parameter tampering or unexpected identity transitions
Contact Uniong support to confirm patched versions and apply vendor-supplied updates as soon as they are released

Patch Information

No specific patched version is enumerated in the public NVD entry at the time of writing. Refer to the TWCERT Security Advisory and the TWCERT Security Alert for vendor remediation guidance and version availability.

Workarounds

Place WebITR behind a reverse proxy or WAF that enforces strict parameter validation on authentication endpoints
Apply IP allow-listing to limit access to the application to known corporate ranges
Enable multi-factor authentication on any upstream identity provider used to access WebITR to raise the cost of obtaining an initial account
Increase audit log retention and review frequency until the vendor patch is deployed and verified

bash

# Example: restrict WebITR access via nginx allow-list and parameter inspection
location /webitr/ {
    allow 10.0.0.0/8;
    deny all;

    if ($arg_userid ~* "[^a-zA-Z0-9_-]") {
        return 400;
    }

    proxy_pass http://webitr-backend;
}