CVE-2026-25197: Authentication Bypass Vulnerability

CVE-2026-25197 Overview

CVE-2026-25197 is an Insecure Direct Object Reference (IDOR) vulnerability affecting an API endpoint that allows authenticated users to access other user profiles by manipulating the id parameter in API calls. This authorization bypass vulnerability enables horizontal privilege escalation, where attackers can pivot from their own authenticated session to view and potentially modify data belonging to other users.

Critical Impact

Authenticated attackers can access sensitive profile data and potentially modify information belonging to any user in the system by simply enumerating user IDs in API requests.

Affected Products

• MyGardyn IoT Platform (specific versions not disclosed)

Discovery Timeline

• 2026-04-03 - CVE-2026-25197 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-25197

Vulnerability Analysis

This vulnerability is classified under CWE-639 (Authorization Bypass Through User-Controlled Key), which occurs when an application uses user-controlled input to directly reference objects without proper authorization checks. In this case, the affected API endpoint accepts a user-supplied id parameter that is used to retrieve user profile data without validating whether the authenticated user has permission to access that particular profile.

The vulnerability allows network-based attacks without requiring any user interaction. An attacker with valid authentication credentials can enumerate user IDs and access profile information for any user in the system, resulting in high confidentiality and integrity impacts.

Root Cause

The root cause of this vulnerability is the lack of proper authorization checks on the API endpoint. The application trusts the user-supplied id parameter without verifying that the authenticated user should have access to the requested profile. This is a classic example of broken access control where authentication is present but authorization validation is missing or insufficient.

The affected endpoint appears to directly use the id value from the request to query the database for user profile information, creating a direct object reference that bypasses intended access controls.

Attack Vector

The attack vector is network-based and requires an authenticated session. An attacker can exploit this vulnerability through the following approach:

1. The attacker first authenticates to the application with valid credentials
2. The attacker observes the API call structure for accessing their own profile, noting the id parameter
3. The attacker modifies the id value to reference other users (e.g., incrementing/decrementing numeric IDs or substituting UUIDs)
4. The API responds with the profile data of the targeted user without authorization checks
5. The attacker can enumerate through user IDs to harvest profile data or potentially modify other users' information

This type of vulnerability is particularly dangerous in IoT platforms where user profile data may include device configurations, location information, and personal details.

Detection Methods for CVE-2026-25197

Indicators of Compromise

• Unusual patterns of API requests to profile endpoints with sequentially enumerated user IDs
• Single authenticated sessions accessing multiple user profiles in rapid succession
• Anomalous spikes in profile endpoint traffic from individual user accounts
• Error responses indicating invalid or non-existent user IDs being probed

Detection Strategies

• Implement API rate limiting and monitor for excessive requests to user profile endpoints
• Deploy Web Application Firewall (WAF) rules to detect ID enumeration patterns
• Enable detailed audit logging for all profile access requests including the requesting user and target profile ID
• Configure alerting for users accessing profiles other than their own

Monitoring Recommendations

• Monitor API access logs for patterns of sequential ID access attempts
• Track authentication token usage across different profile endpoints
• Implement anomaly detection for user behavior that deviates from normal profile access patterns
• Review application logs for authorization failure events that may indicate exploitation attempts

How to Mitigate CVE-2026-25197

Immediate Actions Required

• Review and audit all API endpoints that accept user-controlled identifiers for proper authorization checks
• Implement server-side validation to ensure authenticated users can only access their own profile data
• Consider replacing sequential numeric IDs with non-enumerable identifiers (UUIDs or hashed values)
• Enable enhanced logging and monitoring for profile access endpoints

Patch Information

Refer to the CISA ICS Advisory #ICSA-26-055-03 for official patch and remediation guidance. Additional security information is available at the MyGardyn Security Overview page. Technical details can also be found in the GitHub CSAF File.

Workarounds

• Implement additional authorization middleware to validate user ownership before returning profile data
• Deploy network segmentation to limit API access to trusted network segments
• Enable multi-factor authentication to reduce the risk of credential compromise
• Consider implementing API gateway controls to filter and validate requests before they reach the application

# Example: Add authorization header validation to API proxy configuration
# This is a conceptual example - adapt to your specific infrastructure

# In nginx.conf or API gateway configuration:
# Ensure profile requests are logged with user context
# location /api/v1/profile/ {
#     access_log /var/log/nginx/profile_access.log detailed;
#     # Forward to application with enhanced logging
# }