CVE-2021-27582
📋 TL;DR
CVE-2021-27582 is a mass assignment vulnerability in MITREid Connect's OpenID Connect server that allows attackers to manipulate OAuth authorization parameters during authentication flows. This vulnerability affects all deployments using MITREid Connect version 1.3.3 and earlier. Attackers can potentially bypass intended authorization controls and gain unauthorized access to protected resources.
💻 Affected Systems
- MITREid Connect OpenID Connect Java Spring Server
📦 What is this software?
Connect by Mitreid
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, unauthorized access to protected resources, privilege escalation, and potential data exfiltration from OAuth-protected systems.
Likely Case
Authorization bypass allowing access to resources the user shouldn't have permission to access, potentially leading to data exposure.
If Mitigated
Limited impact with proper input validation and authorization checks in place, though the vulnerability still exists at the framework level.
🎯 Exploit Status
Exploitation requires understanding of OAuth flows and Spring MVC autobinding. The vulnerability is well-documented with public research available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit 7eba3c12fed82388f917e8dd9b73e86e3a311e4c
Vendor Advisory: https://github.com/mitreid-connect/OpenID-Connect-Java-Spring-Server/commit/7eba3c12fed82388f917e8dd9b73e86e3a311e4c
Restart Required: Yes
Instructions:
1. Update to latest MITREid Connect version. 2. Apply the specific commit fix if using custom deployment. 3. Restart the application server. 4. Verify the @ModelAttribute annotations are properly secured.
🔧 Temporary Workarounds
Input Validation Filter
allImplement a servlet filter or Spring interceptor to validate and sanitize all OAuth-related parameters before they reach the controller.
@InitBinder Configuration
allUse Spring's @InitBinder to explicitly control which parameters can be bound to the authorizationRequest object.
🧯 If You Can't Patch
- Implement strict input validation for all OAuth authorization parameters
- Deploy a WAF with rules to detect and block mass assignment attempts in OAuth flows
🔍 How to Verify
Check if Vulnerable:
Check if your MITREid Connect version is 1.3.3 or earlier. Review OAuthConfirmationController.java for unsafe @ModelAttribute usage.Check Version:
Check pom.xml for mitreid-connect version or examine deployed JAR/WAR file metadata.Verify Fix Applied:
Verify the application uses version after the fix commit. Test OAuth flows to ensure parameters cannot be manipulated.📡 Detection & Monitoring
Log Indicators:
- Unusual OAuth parameter combinations
- Authorization requests with unexpected scope or client_id values
- Failed authorization attempts with manipulated parameters
Network Indicators:
- HTTP requests with excessive or unusual OAuth parameters
- Patterns of authorization flow manipulation
SIEM Query:
source="oauth_server" AND (param_count>10 OR contains(param_names,"unexpected_parameter"))🔗 References
- http://agrrrdog.blogspot.com/2017/03/autobinding-vulns-and-spring-mvc.html
- https://github.com/mitreid-connect/OpenID-Connect-Java-Spring-Server/commit/7eba3c12fed82388f917e8dd9b73e86e3a311e4c
- https://portswigger.net/research/hidden-oauth-attack-vectors
- http://agrrrdog.blogspot.com/2017/03/autobinding-vulns-and-spring-mvc.html
- https://github.com/mitreid-connect/OpenID-Connect-Java-Spring-Server/commit/7eba3c12fed82388f917e8dd9b73e86e3a311e4c
- https://portswigger.net/research/hidden-oauth-attack-vectors
