CVE-2025-5518 Overview
CVE-2025-5518 is an Authorization Bypass Through User-Controlled Key vulnerability [CWE-639] in ArgusTech BILGER versions prior to 2.4.6. Authenticated users with low privileges can manipulate trusted identifiers in requests to access resources belonging to other users. This class of flaw is commonly referred to as an Insecure Direct Object Reference (IDOR).
The vulnerability is exploitable over the network with low attack complexity and requires only user-level privileges. Successful exploitation results in high confidentiality impact, while integrity and availability remain unaffected. Public proof-of-concept material has been referenced in third-party repositories, increasing exposure risk for unpatched deployments.
Critical Impact
Authenticated attackers can bypass authorization checks by tampering with user-controlled identifiers, exposing sensitive data belonging to other application users.
Affected Products
- ArgusTech BILGER versions before 2.4.6
Discovery Timeline
- 2025-09-16 - CVE-2025-5518 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-5518
Vulnerability Analysis
The flaw arises because BILGER trusts user-supplied identifiers when authorizing access to resources. An authenticated attacker substitutes another user's identifier in a request parameter and the application returns data without verifying ownership. This pattern maps to [CWE-639: Authorization Bypass Through User-Controlled Key].
Exploitation requires only valid low-privilege credentials and a network path to the application. No user interaction or elevated privileges are needed, and the vulnerability can be triggered through standard HTTP requests using tools such as a browser proxy or command-line HTTP client.
Root Cause
The root cause is missing server-side authorization enforcement on object references. BILGER accepts identifiers such as record IDs, account numbers, or resource handles from client input and uses them directly in backend lookups. The application fails to validate that the authenticated session owns the referenced object before returning data.
Attack Vector
An attacker authenticates to the application with any valid user account. The attacker then intercepts a legitimate request and modifies the identifier parameter to reference another user's resource. Because the server relies on the client-supplied identifier as a trusted key, it returns the requested data without a permission check.
Refer to the published security notifications from Siber Güvenlik and USOM for additional technical context. Public proof-of-concept material is referenced at Tiger-Foxx PoC repository and M4rgs PoC repository.
Detection Methods for CVE-2025-5518
Indicators of Compromise
- Sequential or enumerated identifier values in HTTP request parameters from a single authenticated session.
- Application access logs showing a user account retrieving records associated with other user IDs.
- Unusual response sizes or object types returned to a session that historically accessed a narrow set of resources.
Detection Strategies
- Instrument the application to log the authenticated user ID alongside the object ID for every resource access, then alert when they diverge.
- Deploy web application firewall rules that flag rapid iteration of identifier parameters within a short time window.
- Correlate authentication events with data-access events to identify sessions retrieving disproportionate volumes of records.
Monitoring Recommendations
- Monitor BILGER instances for anomalous request patterns targeting endpoints that expose numeric or predictable identifiers.
- Baseline normal per-user access volumes and alert on statistical outliers.
- Retain application access logs long enough to support retrospective investigation of suspected IDOR activity.
How to Mitigate CVE-2025-5518
Immediate Actions Required
- Upgrade ArgusTech BILGER to version 2.4.6 or later.
- Audit application access logs for evidence of cross-account resource retrieval prior to patch deployment.
- Rotate credentials and session tokens for any accounts observed accessing resources outside their scope.
Patch Information
ArgusTech addresses CVE-2025-5518 in BILGER version 2.4.6. Administrators should apply the vendor update as the primary remediation. Consult the vendor and the USOM Security Notification for release details.
Workarounds
- Restrict network access to the BILGER application to trusted user populations using VPN or IP allow-listing.
- Enforce short session lifetimes and require re-authentication for sensitive actions until patching is complete.
- Add reverse-proxy or WAF policies that inspect and rate-limit requests containing predictable identifier parameters.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
