CVE-2023-22527
📋 TL;DR
This is a critical template injection vulnerability (CWE-74) in older Confluence Data Center and Server versions that allows unauthenticated attackers to execute arbitrary code remotely. Affected organizations using vulnerable versions face immediate risk of complete system compromise. Only older versions are affected, with current supported versions already patched.
💻 Affected Systems
- Confluence Data Center
- Confluence Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with attacker gaining full control of the Confluence server, data exfiltration, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to data theft, service disruption, and potential ransomware deployment.
If Mitigated
No impact if running patched versions or proper network segmentation prevents exploitation.
🎯 Exploit Status
Public exploit code exists on Packet Storm Security, making this easily weaponizable by attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Latest supported versions (specific version numbers should be checked in Atlassian advisory)
Vendor Advisory: https://confluence.atlassian.com/pages/viewpage.action?pageId=1333335615
Restart Required: Yes
Instructions:
1. Check current Confluence version. 2. Backup data and configuration. 3. Upgrade to latest supported version following Atlassian upgrade guide. 4. Restart Confluence service. 5. Verify upgrade success.
🔧 Temporary Workarounds
Network Isolation
allRestrict network access to Confluence instances to only trusted IP addresses
Use firewall rules to block external access: iptables -A INPUT -p tcp --dport 8090 -s !TRUSTED_IP -j DROP
Web Application Firewall
allDeploy WAF with template injection protection rules
🧯 If You Can't Patch
- Immediately isolate affected systems from internet and restrict internal network access
- Implement strict monitoring for suspicious template-related activity and command execution attempts
🔍 How to Verify
Check if Vulnerable:
Check Confluence version against Atlassian's security advisory. If running older version (pre-mitigation), assume vulnerable.Check Version:
Check Confluence administration console or view confluence/WEB-INF/classes/build.propertiesVerify Fix Applied:
Confirm Confluence version is updated to latest supported release and no longer matches vulnerable version range.📡 Detection & Monitoring
Log Indicators:
- Unusual template rendering errors
- Suspicious HTTP requests with template syntax
- Unexpected process execution in system logs
Network Indicators:
- HTTP requests containing template injection payloads
- Outbound connections from Confluence to unknown destinations
SIEM Query:
source="confluence.log" AND ("template" OR "velocity" OR "freemarker") AND (error OR exception)🔗 References
- http://packetstormsecurity.com/files/176789/Atlassian-Confluence-SSTI-Injection.html
- https://confluence.atlassian.com/pages/viewpage.action?pageId=1333335615
- https://jira.atlassian.com/browse/CONFSERVER-93833
- http://packetstormsecurity.com/files/176789/Atlassian-Confluence-SSTI-Injection.html
- https://confluence.atlassian.com/pages/viewpage.action?pageId=1333335615
- https://jira.atlassian.com/browse/CONFSERVER-93833
- https://www.vicarius.io/vsociety/posts/pwning-confluence-via-ognl-injection-for-fun-and-learning-cve-2023-22527
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-22527
