CVE-2015-20110
📋 TL;DR
CVE-2015-20110 is a timing attack vulnerability in JHipster's token validation that allows attackers to brute-force authentication tokens character by character. By measuring response time differences during token comparison, attackers can drastically reduce the search space from exponential to linear complexity. This affects all JHipster applications using the vulnerable generator-jhipster versions for token-based authentication.
💻 Affected Systems
- JHipster generator-jhipster
📦 What is this software?
Jhipster by Jhipster
⚠️ Risk & Real-World Impact
Worst Case
Complete authentication bypass leading to unauthorized access to user accounts, administrative functions, or sensitive data exposure.
Likely Case
Targeted account takeover of specific users through token guessing, potentially leading to data theft or privilege escalation.
If Mitigated
Minimal impact with proper network controls, rate limiting, and monitoring in place to detect timing attack attempts.
🎯 Exploit Status
Exploitation requires the ability to send authentication requests and measure timing differences with high precision. Attackers need to be able to interact with the authentication endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.23.0 and later
Vendor Advisory: https://github.com/jhipster/generator-jhipster/security/advisories
Restart Required: Yes
Instructions:
1. Update generator-jhipster to version 2.23.0 or later using 'npm update generator-jhipster'. 2. Regenerate your JHipster application with the updated version. 3. Redeploy the application with the new generated code. 4. Restart all application instances.
🔧 Temporary Workarounds
Implement constant-time token comparison
allReplace the vulnerable string comparison with a constant-time comparison function that always takes the same amount of time regardless of input.
Implement crypto.timingSafeEqual() or equivalent constant-time comparison in your token validation logic
Add request rate limiting
allImplement strict rate limiting on authentication endpoints to make timing attacks impractical.
Configure rate limiting middleware (e.g., express-rate-limit for Node.js) with low thresholds for authentication endpoints
🧯 If You Can't Patch
- Implement network-level rate limiting and WAF rules to detect and block timing attack patterns
- Monitor authentication logs for unusual patterns of failed token validation attempts
🔍 How to Verify
Check if Vulnerable:
Check your package.json for generator-jhipster version. If version is less than 2.23.0 and you use token authentication, you are vulnerable.Check Version:
npm list generator-jhipster | grep generator-jhipsterVerify Fix Applied:
Verify generator-jhipster version is 2.23.0 or higher in package.json and check that token validation uses constant-time comparison in the source code.📡 Detection & Monitoring
Log Indicators:
- Multiple failed token validation attempts from single IP
- Unusual timing patterns in authentication requests
- Token validation failures with similar prefix patterns
Network Indicators:
- High volume of authentication requests to token validation endpoints
- Requests with systematically varying token values
SIEM Query:
source="application_logs" AND (message="Token validation failed" OR message="Invalid token") | stats count by src_ip | where count > 100🔗 References
- https://github.com/jhipster/generator-jhipster/commit/79fe5626cb1bb80f9ac86cf46980748e65d2bdbc
- https://github.com/jhipster/generator-jhipster/commit/7c49ab3d45dc4921b831a2ca55fb1e2a2db1ee25
- https://github.com/jhipster/generator-jhipster/compare/v2.22.0...v2.23.0
- https://github.com/jhipster/generator-jhipster/issues/2095
- https://github.com/jhipster/generator-jhipster/commit/79fe5626cb1bb80f9ac86cf46980748e65d2bdbc
- https://github.com/jhipster/generator-jhipster/commit/7c49ab3d45dc4921b831a2ca55fb1e2a2db1ee25
- https://github.com/jhipster/generator-jhipster/compare/v2.22.0...v2.23.0
- https://github.com/jhipster/generator-jhipster/issues/2095
