CVE-2023-20859
📋 TL;DR
Spring Vault applications that attempt to revoke Vault batch tokens may inadvertently log sensitive information. This affects applications using Spring Vault 3.0.x before 3.0.2, 2.3.x before 2.3.3, and older versions. The vulnerability exposes sensitive data in log files that could be accessed by unauthorized users.
💻 Affected Systems
- Spring Vault
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Sensitive Vault credentials or tokens are exposed in log files, potentially leading to full Vault access compromise and data exfiltration.
Likely Case
Sensitive token information appears in application logs, increasing risk of credential exposure if logs are improperly secured.
If Mitigated
Minimal impact if proper log access controls and monitoring are in place to prevent unauthorized log access.
🎯 Exploit Status
Exploitation requires access to log files where sensitive information is written. No special tools or techniques needed beyond log access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Spring Vault 3.0.2 or 2.3.3
Vendor Advisory: https://spring.io/security/cve-2023-20859
Restart Required: Yes
Instructions:
1. Update Spring Vault dependency to version 3.0.2 or 2.3.3. 2. Update pom.xml or build.gradle with new version. 3. Rebuild and redeploy application. 4. Restart affected services.
🔧 Temporary Workarounds
Disable batch token revocation logging
allConfigure logging to exclude sensitive information from batch token revocation operations
Configure logback.xml or log4j2.xml to filter out sensitive patterns from Vault operations
Restrict log file access
linuxImplement strict file permissions and access controls on application log files
chmod 600 application.log
setfacl -m u:appuser:rw application.log
🧯 If You Can't Patch
- Implement strict access controls on log directories and files
- Configure log aggregation systems to filter or mask sensitive Vault-related information
🔍 How to Verify
Check if Vulnerable:
Check Spring Vault version in pom.xml, build.gradle, or application dependencies. If using 3.0.x < 3.0.2 or 2.3.x < 2.3.3, you are vulnerable.Check Version:
mvn dependency:tree | grep spring-vault OR gradle dependencies | grep spring-vaultVerify Fix Applied:
Verify Spring Vault version is 3.0.2 or higher (for 3.x) or 2.3.3 or higher (for 2.x). Test batch token revocation and check logs for sensitive information.📡 Detection & Monitoring
Log Indicators:
- Sensitive token strings appearing in application logs
- Vault batch token revocation operations in logs with token details
Network Indicators:
- Unusual access patterns to log files or directories
SIEM Query:
source="application.log" AND "batch token" AND ("revoke" OR "sensitive")