CVE-2023-20873
📋 TL;DR
This vulnerability allows security bypass in Spring Boot applications deployed to Cloud Foundry. Attackers could potentially bypass authentication or authorization controls. Affected users include those running Spring Boot 3.0.0-3.0.5, 2.7.0-2.7.10, and older unsupported versions on Cloud Foundry.
💻 Affected Systems
- Spring Boot
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the application allowing unauthorized access to sensitive data and functionality, potentially leading to data exfiltration or system takeover.
Likely Case
Authentication or authorization bypass allowing unauthorized access to restricted application endpoints or functionality.
If Mitigated
Minimal impact if proper network segmentation, additional authentication layers, and monitoring are in place.
🎯 Exploit Status
The vulnerability appears to be configuration-specific to Cloud Foundry deployments. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.0.6+ for 3.0.x, 2.7.11+ for 2.7.x
Vendor Advisory: https://spring.io/security/cve-2023-20873
Restart Required: Yes
Instructions:
1. Update Spring Boot dependency to 3.0.6+ (for 3.0.x) or 2.7.11+ (for 2.7.x). 2. Rebuild your application. 3. Redeploy to Cloud Foundry. 4. Restart the application.
🔧 Temporary Workarounds
Remove Cloud Foundry deployment
allDeploy the application using alternative methods not affected by this vulnerability
Implement additional authentication layer
allAdd API gateway or reverse proxy with authentication before the Spring Boot application
🧯 If You Can't Patch
- Isolate the vulnerable application using network segmentation and firewall rules
- Implement strict monitoring and alerting for authentication bypass attempts
🔍 How to Verify
Check if Vulnerable:
Check Spring Boot version in pom.xml or build.gradle and verify deployment is on Cloud FoundryCheck Version:
For Maven: mvn dependency:tree | grep spring-boot. For Gradle: ./gradlew dependencies | grep spring-bootVerify Fix Applied:
Verify Spring Boot version is 3.0.6+ or 2.7.11+ after update and redeployment📡 Detection & Monitoring
Log Indicators:
- Unexpected authentication bypass attempts
- Access to restricted endpoints without proper authentication logs
Network Indicators:
- Unusual traffic patterns to Cloud Foundry routes
- Requests bypassing expected authentication flows
SIEM Query:
source="spring-boot-logs" AND (event_type="AUTHENTICATION_BYPASS" OR status_code=200 AND request_path IN ("/admin/*", "/api/restricted/*") AND user="anonymous")🔗 References
- https://security.netapp.com/advisory/ntap-20230601-0009/
- https://spring.io/blog/2023/05/18/spring-boot-2-5-15-and-2-6-15-available-now
- https://spring.io/security/cve-2023-20873
- https://security.netapp.com/advisory/ntap-20230601-0009/
- https://spring.io/blog/2023/05/18/spring-boot-2-5-15-and-2-6-15-available-now
- https://spring.io/security/cve-2023-20873
