CVE-2024-38827
📋 TL;DR
This vulnerability involves locale-specific case conversion inconsistencies in Java's String.toLowerCase() and String.toUpperCase() methods, which can cause authorization rules to fail when comparing strings with different case mappings. It affects Spring Security applications that rely on case-insensitive string comparisons for authorization decisions. The impact is authorization bypass in specific locale contexts.
💻 Affected Systems
- Spring Security
- Applications using Spring Security with case-insensitive authorization checks
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could bypass authorization controls and access restricted resources or perform unauthorized actions by exploiting locale-specific case conversion edge cases.
Likely Case
Authorization rules may fail inconsistently for users with specific locale settings, potentially allowing unintended access to some protected endpoints.
If Mitigated
With proper input validation and case normalization using Locale.ROOT, the vulnerability impact is minimal to non-existent.
🎯 Exploit Status
Exploitation requires specific locale conditions and knowledge of the application's authorization logic. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Spring Security 6.2.4, 6.1.11, or later
Vendor Advisory: https://spring.io/security/cve-2024-38827
Restart Required: Yes
Instructions:
1. Update Spring Security dependency to version 6.2.4 or 6.1.11 or later. 2. Update pom.xml or build.gradle with the new version. 3. Rebuild and redeploy the application. 4. Restart the application server.
🔧 Temporary Workarounds
Use Locale.ROOT for case conversion
allModify code to use Locale.ROOT when performing case conversions for authorization comparisons
// Replace: string.toLowerCase()
// With: string.toLowerCase(Locale.ROOT)
// Replace: string.toUpperCase()
// With: string.toUpperCase(Locale.ROOT)
🧯 If You Can't Patch
- Implement custom authorization logic that uses Locale.ROOT for all case conversions
- Add input validation to reject strings that could trigger locale-specific case conversion anomalies
🔍 How to Verify
Check if Vulnerable:
Check if your application uses String.toLowerCase() or String.toUpperCase() without Locale parameter in authorization logic, particularly in Spring Security configurations.Check Version:
Check pom.xml or build.gradle for spring-security version, or run: java -cp "path/to/spring-security*.jar" org.springframework.security.core.SpringVersionVerify Fix Applied:
Verify Spring Security version is 6.2.4+, 6.1.11+, or that all case conversions in authorization logic use Locale.ROOT parameter.📡 Detection & Monitoring
Log Indicators:
- Unusual authorization failures or successes with Turkish or similar locale users
- Access logs showing users accessing endpoints they shouldn't have permissions for
Network Indicators:
- HTTP requests with locale-specific headers (Accept-Language) accessing protected resources
SIEM Query:
source="application.logs" AND ("authorization failed" OR "access denied") AND (locale="tr" OR locale="az")