CVE-2025-39503
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code via PHP object injection through deserialization of untrusted data in the Goodlayers Hotel WordPress plugin. All WordPress sites running affected versions of the plugin are vulnerable to exploitation.
💻 Affected Systems
- Goodlayers Hotel WordPress Plugin
⚠️ 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 server compromise leading to data theft, ransomware deployment, or website defacement
Likely Case
Remote code execution allowing attacker to create backdoors, install malware, or pivot to internal networks
If Mitigated
Limited impact if proper network segmentation and WAF rules block exploitation attempts
🎯 Exploit Status
Public exploit details available on security research sites; CVSS 9.8 indicates trivial exploitation
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.1.5 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel
2. Navigate to Plugins → Installed Plugins
3. Find Goodlayers Hotel plugin
4. Click 'Update Now' if update available
5. If no update available, deactivate and delete plugin immediately
🔧 Temporary Workarounds
Disable Plugin
allDeactivate the vulnerable plugin to prevent exploitation
wp plugin deactivate gdlr-hotel
WAF Rule for Deserialization
allBlock PHP object injection attempts at web application firewall
Add rule to block requests containing 'O:' followed by numbers (PHP serialized objects)
🧯 If You Can't Patch
- Remove plugin files from server completely
- Implement strict network segmentation and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Goodlayers Hotel version. If version ≤3.1.4, vulnerableCheck Version:
wp plugin list --name=gdlr-hotel --field=versionVerify Fix Applied:
Confirm plugin version is 3.1.5 or higher in WordPress admin📡 Detection & Monitoring
Log Indicators:
- POST requests containing serialized PHP objects (O:)
- Unexpected file creation in wp-content/uploads
- Suspicious PHP process execution
Network Indicators:
- HTTP requests with serialized data in parameters
- Outbound connections from WordPress server to unknown IPs
SIEM Query:
source="web_logs" AND (uri="*gdlr-hotel*" OR post_data="*O:*")