CVE-2025-4596: Asseco ADMX Auth Bypass Vulnerability

CVE-2025-4596 Overview

CVE-2025-4596 is an Insecure Direct Object Reference (IDOR) vulnerability affecting the Asseco ADMX medical records processing system. The vulnerability allows authenticated users to access medical files belonging to other users by manipulating GET request parameters containing document IDs. This represents a significant privacy breach vector in healthcare environments where patient data confidentiality is paramount.

Critical Impact

Authenticated users can access unauthorized medical records by manipulating document ID parameters, potentially exposing sensitive patient health information and violating healthcare data protection regulations.

Affected Products

• Asseco ADMX versions prior to 6.09.01.62
• Medical records processing systems utilizing vulnerable ADMX deployments
• Healthcare information management infrastructure dependent on affected ADMX versions

Discovery Timeline

• 2026-01-08 - CVE CVE-2025-4596 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-4596

Vulnerability Analysis

This vulnerability falls under CWE-639 (Authorization Bypass Through User-Controlled Key), a category of access control flaws where the application relies on user-supplied input to determine authorization decisions. In the case of Asseco ADMX, the system fails to properly validate whether the requesting user has legitimate access rights to the medical document specified in the GET request parameters.

The attack can be executed over the network without user interaction, requiring only low-privilege authenticated access. The vulnerability specifically impacts data confidentiality, allowing unauthorized disclosure of medical records. While the integrity and availability of the system remain unaffected, the exposure of protected health information represents a serious compliance and privacy concern.

Root Cause

The root cause of CVE-2025-4596 is inadequate authorization validation in the document retrieval functionality. The ADMX system accepts document IDs directly from user-controlled GET parameters and retrieves the corresponding medical files without verifying that the authenticated user has proper authorization to access those specific documents. This design flaw assumes that possession of a valid session and knowledge of a document ID constitutes sufficient authorization.

Attack Vector

The attack exploits the predictable or enumerable nature of document IDs in GET request parameters. An attacker with valid credentials to the ADMX system can:

1. Authenticate to the ADMX application using legitimate credentials
2. Observe the URL structure when accessing their own medical documents
3. Identify the GET parameter containing the document ID
4. Systematically modify the document ID value to reference other users' records
5. Access medical files belonging to other patients without proper authorization

The vulnerability mechanism involves direct manipulation of URL parameters. When a user requests a document, the system retrieves it based solely on the provided ID without checking ownership or access permissions. For technical implementation details, refer to the CERT Poland CVE-2025-4596 Analysis.

Detection Methods for CVE-2025-4596

Indicators of Compromise

• Unusual patterns of document access requests from single user sessions
• Sequential or systematic document ID enumeration in access logs
• Users accessing documents outside their normal access patterns
• High volume of document retrieval requests in short time periods
• Access attempts to document IDs not associated with the requesting user's profile

Detection Strategies

• Implement web application firewall rules to detect parameter manipulation patterns
• Deploy user behavior analytics to identify anomalous document access patterns
• Enable detailed audit logging for all document retrieval operations
• Monitor for sequential or brute-force patterns in document ID requests
• Configure alerts for users accessing documents outside their authorized scope

Monitoring Recommendations

• Review application access logs for evidence of document ID enumeration
• Establish baseline user document access patterns for anomaly detection
• Implement real-time alerting for high-frequency document access requests
• Correlate authentication events with subsequent document access patterns
• Regularly audit user access to ensure alignment with authorized permissions

How to Mitigate CVE-2025-4596

Immediate Actions Required

• Upgrade Asseco ADMX to version 6.09.01.62 or later immediately
• Conduct an audit of document access logs to identify potential exploitation
• Review user access patterns for signs of unauthorized document retrieval
• Implement additional access controls at the network level if immediate patching is not possible
• Notify affected patients if unauthorized access to medical records is confirmed

Patch Information

Asseco has addressed this vulnerability in ADMX version 6.09.01.62. Organizations running vulnerable versions should prioritize upgrading to this patched release. The fix implements proper authorization validation to ensure users can only access documents they are explicitly permitted to view. For additional details, consult the CERT Poland CVE-2025-4596 Analysis.

Workarounds

• Implement web application firewall rules to restrict document ID parameter manipulation
• Deploy additional authentication layers for document access functionality
• Enable enhanced logging and monitoring to detect exploitation attempts
• Restrict network access to the ADMX system to trusted IP ranges
• Consider implementing document-level access control at the database layer as a defense-in-depth measure

# Example: WAF rule to detect sequential document ID access patterns
# Add to your web application firewall configuration
# This rule monitors for rapid sequential document ID requests which may indicate enumeration

# Log all document access requests for audit purposes
# Ensure your ADMX deployment logs include user identity and document IDs accessed
# Review logs regularly: grep -E "document_id=" /var/log/admx/access.log | sort | uniq -c | sort -rn