CVE-2023-38693
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Lucee Server by exploiting an XML External Entity (XXE) vulnerability in the REST endpoint. Attackers can read files, perform server-side request forgery, or achieve remote code execution. All Lucee Server instances with vulnerable versions are affected.
💻 Affected Systems
- Lucee Server
⚠️ 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
Complete system compromise allowing attackers to execute arbitrary commands, access sensitive data, pivot to internal networks, and maintain persistent access.
Likely Case
Remote code execution leading to data theft, service disruption, or deployment of malware/backdoors on affected servers.
If Mitigated
Limited impact if proper network segmentation, input validation, and security controls prevent exploitation attempts.
🎯 Exploit Status
Exploitation requires sending specially crafted XML to the REST endpoint, which is straightforward for attackers with basic XXE knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.4.3.2, 5.3.12.1, 5.3.7.59, 5.3.8.236, or 5.3.9.173
Vendor Advisory: https://github.com/lucee/Lucee/security/advisories/GHSA-vwjx-mmwm-pwrf
Restart Required: Yes
Instructions:
1. Identify current Lucee version. 2. Download appropriate patched version from official Lucee website. 3. Backup current installation. 4. Stop Lucee service. 5. Install patched version. 6. Restart Lucee service. 7. Verify successful update.
🔧 Temporary Workarounds
Disable REST Endpoint
allTemporarily disable the vulnerable REST endpoint if not required
Edit lucee-web.xml.cfm and set restEnable to false
XML Input Validation
allImplement XML parsing with external entity processing disabled
Configure XML parser to disable DTD and external entity resolution
🧯 If You Can't Patch
- Implement strict network access controls to restrict access to Lucee REST endpoints
- Deploy web application firewall with XXE protection rules
🔍 How to Verify
Check if Vulnerable:
Check Lucee version against affected versions list. Test REST endpoint with XXE payloads if authorized.Check Version:
Check Lucee Administrator interface or examine lucee-web.xml.cfm for version informationVerify Fix Applied:
Verify Lucee version is patched. Test REST endpoint with XXE payloads to confirm they are blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual XML payloads to REST endpoints
- External entity references in XML requests
- Unexpected file read attempts
Network Indicators:
- XML requests containing SYSTEM or PUBLIC DTD declarations
- Requests to internal resources from Lucee server
SIEM Query:
source="lucee.log" AND ("XXE" OR "external entity" OR "DOCTYPE")