CVE-2025-42605: Meon Bidding Solutions Auth Bypass Flaw

CVE-2025-42605 Overview

This vulnerability exists in Meon Bidding Solutions due to improper authorization controls on certain API endpoints for the initiation, modification, or cancellation operations. An authenticated remote attacker could exploit this vulnerability by manipulating parameters in the API request body to gain unauthorized access to other user accounts.

Successful exploitation of this vulnerability could allow a remote attacker to perform unauthorized manipulation of data associated with other user accounts. This represents a significant Insecure Direct Object Reference (IDOR) vulnerability classified under CWE-639: Authorization Bypass Through User-Controlled Key.

Critical Impact

Authenticated attackers can bypass authorization controls to access and manipulate data belonging to other users, potentially compromising the integrity and confidentiality of the entire bidding platform.

Affected Products

• Meon Bidding Solutions (specific versions not disclosed)

Discovery Timeline

• 2025-04-23 - CVE-2025-42605 published to NVD
• 2025-04-23 - Last updated in NVD database

Technical Details for CVE-2025-42605

Vulnerability Analysis

The vulnerability stems from insufficient authorization validation on API endpoints responsible for critical bidding operations. When users interact with the Meon Bidding Solutions platform to initiate, modify, or cancel bids, the application fails to properly verify that the requesting user has legitimate access to the targeted resources.

This type of authorization bypass, categorized as CWE-639 (Authorization Bypass Through User-Controlled Key), occurs when an application uses user-supplied input to determine which resource to access without adequately verifying that the user is authorized to access that specific resource. In this case, authenticated users can manipulate API request parameters to reference resources belonging to other accounts.

The vulnerability affects network-accessible API endpoints, making it exploitable remotely by any authenticated user on the platform.

Root Cause

The root cause is improper authorization controls where the application trusts user-supplied identifiers in API requests without performing adequate server-side verification of resource ownership. The system likely relies solely on authentication (verifying user identity) without implementing proper authorization checks (verifying user permissions for specific resources).

This architectural flaw allows horizontal privilege escalation, where an authenticated user can access resources at the same privilege level but belonging to different user accounts.

Attack Vector

The attack vector involves an authenticated attacker manipulating parameters within API request bodies to reference resources belonging to other users. The attacker would:

1. Authenticate legitimately to the Meon Bidding Solutions platform
2. Intercept or craft API requests for bidding operations (initiation, modification, or cancellation)
3. Modify resource identifiers (such as user IDs, bid IDs, or account references) in the request body
4. Submit the manipulated request to gain unauthorized access to other users' data

Since the vulnerability is network-accessible and requires no user interaction, attacks can be automated to enumerate and access multiple victim accounts systematically.

Detection Methods for CVE-2025-42605

Indicators of Compromise

• Unusual patterns of API requests where a single authenticated session accesses resources belonging to multiple different user accounts
• Rapid successive API calls with incrementing or sequential resource identifiers suggesting enumeration attempts
• API access logs showing users modifying or canceling bids they did not create
• Anomalous data modifications appearing in user accounts without corresponding legitimate user sessions

Detection Strategies

• Implement API request logging that correlates authenticated user sessions with accessed resource ownership
• Deploy anomaly detection to identify users accessing resources outside their normal operational patterns
• Monitor for automated enumeration patterns such as sequential ID access or high-volume API requests from single sessions
• Utilize Web Application Firewall (WAF) rules to detect parameter tampering attempts on sensitive API endpoints

Monitoring Recommendations

• Enable detailed audit logging for all bidding-related API endpoints capturing both request parameters and authenticated user context
• Implement real-time alerting for cross-account resource access attempts
• Establish baseline behavioral profiles for API usage patterns to identify deviations indicative of exploitation
• Review API access logs regularly for signs of unauthorized data manipulation across user accounts

How to Mitigate CVE-2025-42605

Immediate Actions Required

• Review and restrict access to affected API endpoints until proper authorization controls can be implemented
• Implement server-side validation to verify that authenticated users can only access resources they own
• Audit existing user data for signs of unauthorized access or modification
• Enable enhanced logging on all bidding-related API endpoints to detect ongoing exploitation attempts

Patch Information

Organizations using Meon Bidding Solutions should contact the vendor directly for patch availability and remediation guidance. Additional information is available in the CERT-IN Vulnerability Note CIVN-2025-0082.

Workarounds

• Implement network-level access controls to restrict API access to trusted IP ranges where feasible
• Deploy a Web Application Firewall (WAF) with rules to detect and block parameter manipulation attempts
• Add additional authorization middleware that validates resource ownership before processing API requests
• Consider implementing rate limiting on sensitive API endpoints to slow down enumeration attempts
• Conduct a security review of all API endpoints to identify and remediate similar authorization bypass vulnerabilities