CVE-2025-5519: BILGER Information Disclosure Vulnerability

CVE-2025-5519 Overview

CVE-2025-5519 is an information disclosure vulnerability in ArgusTech BILGER versions before 2.4.6. The flaw allows a remote attacker to choose a message identifier and retrieve sensitive information inserted into sent data. The weakness is classified as [CWE-201] Insertion of Sensitive Information Into Sent Data. The vulnerability is exploitable over the network without authentication or user interaction, resulting in confidentiality and availability impact.

Critical Impact
Unauthenticated remote attackers can enumerate message identifiers to access sensitive information handled by the BILGER application, potentially exposing confidential business data.

Affected Products

ArgusTech BILGER versions prior to 2.4.6

Discovery Timeline

2025-09-16 - CVE-2025-5519 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-5519

Vulnerability Analysis

The vulnerability resides in how ArgusTech BILGER handles message identifiers within its request handling logic. An attacker can supply an arbitrary message identifier and receive back sensitive information that should not be exposed to the requester. Because the application does not enforce access control checks tied to the requester's session or permissions, message data intended for other users or contexts can be retrieved.

The issue is reachable over the network without prior authentication or user interaction. Attack complexity is low, meaning no specialized conditions are required for successful exploitation. Exploitation results in limited confidentiality loss and limited availability impact, while integrity is not affected.

At publication, the EPSS score sits at 0.335%, indicating a low near-term likelihood of observed exploitation, though the unauthenticated network vector warrants prompt remediation.

Root Cause

The root cause is missing authorization on message identifier lookups [CWE-201]. The application accepts client-supplied identifiers and returns the corresponding message data without validating that the requester is authorized to access that particular message. This design allows enumeration of sensitive information by iterating identifier values.

Attack Vector

An unauthenticated remote attacker sends crafted requests to the BILGER application, supplying chosen message identifiers. The application responds with sensitive information tied to those identifiers. Because no authentication is required and the request is a standard network interaction, exploitation can be automated to enumerate many identifiers rapidly.

No public proof-of-concept exploit code has been published for this issue. Refer to the Siber Güvenlik Advisory TR-25-0250 and the USOM Notification TR-25-0250 for advisory details.

Detection Methods for CVE-2025-5519

Indicators of Compromise

Repeated sequential or randomized requests to BILGER message endpoints from a single source IP
Unusually high volume of HTTP responses containing message payloads served to unauthenticated sessions
Access log entries referencing message identifiers outside the normal range associated with a given user session

Detection Strategies

Deploy web server and application logging to capture full request URIs, query parameters, and response sizes for BILGER endpoints handling message identifiers
Alert on enumeration patterns such as monotonically increasing identifier values or high request rates against message retrieval endpoints
Correlate unauthenticated requests that return sensitive payloads with source IP reputation data

Monitoring Recommendations

Baseline normal request volumes and identifier ranges for the BILGER application, then alert on deviations
Forward BILGER application and proxy logs to a centralized SIEM for retention and analytics
Monitor outbound response sizes on message endpoints to detect bulk information retrieval

How to Mitigate CVE-2025-5519

Immediate Actions Required

Upgrade ArgusTech BILGER to version 2.4.6 or later, which addresses the information disclosure issue
Restrict network exposure of the BILGER application to trusted networks or VPN users until patching is complete
Review historical access logs for evidence of enumeration or unauthorized message retrieval

Patch Information

ArgusTech has addressed the vulnerability in BILGER version 2.4.6. Administrators should apply the vendor update as documented in the Siber Güvenlik Advisory TR-25-0250. Verify the running version after upgrade and confirm that message identifier requests now enforce authorization checks.

Workarounds

Place the BILGER application behind an authenticating reverse proxy that validates user identity before requests reach the application
Apply web application firewall rules to block unauthenticated access to message identifier endpoints
Rate-limit requests to message retrieval endpoints to slow enumeration attempts

bash

# Example NGINX rule to require authentication and rate-limit message endpoints
limit_req_zone $binary_remote_addr zone=bilger_msg:10m rate=10r/m;

location /bilger/message/ {
    limit_req zone=bilger_msg burst=5 nodelay;
    auth_request /auth;
    proxy_pass http://bilger_backend;
}