CVE-2025-4279
📋 TL;DR
The External Image Replace WordPress plugin allows authenticated attackers with contributor-level permissions or higher to upload arbitrary files due to missing file type validation. This vulnerability can lead to remote code execution on affected WordPress sites. All versions up to and including 1.0.8 are vulnerable.
💻 Affected Systems
- WordPress External Image Replace 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
Full server compromise via remote code execution, allowing attackers to install malware, steal data, or pivot to other systems.
Likely Case
Website defacement, backdoor installation, or data exfiltration through uploaded malicious files.
If Mitigated
Limited impact if file uploads are restricted at server level or plugin is disabled.
🎯 Exploit Status
Exploitation requires contributor-level access. The vulnerability is straightforward to exploit once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.9 or later
Vendor Advisory: https://plugins.trac.wordpress.org/browser/external-image-replace/tags/1.0.9/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins. 3. Find 'External Image Replace'. 4. Click 'Update Now' if available. 5. If no update appears, manually download version 1.0.9+ from WordPress.org and replace the plugin files.
🔧 Temporary Workarounds
Disable the plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate external-image-replace
Restrict file uploads at server level
linuxConfigure web server to block execution of uploaded files in upload directories
# In .htaccess for Apache: Options -ExecCGI -Includes -Indexes
# In nginx config: location ~* \.(php|phtml|php3|php4|php5|php7)$ { deny all; }
🧯 If You Can't Patch
- Remove contributor role from untrusted users
- Implement web application firewall rules to block suspicious file uploads
🔍 How to Verify
Check if Vulnerable:
Check plugin version in WordPress admin under Plugins > Installed Plugins. If version is 1.0.8 or lower, you are vulnerable.Check Version:
wp plugin get external-image-replace --field=versionVerify Fix Applied:
Verify plugin version is 1.0.9 or higher. Test file upload functionality with non-image files to confirm validation is working.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to wp-content/uploads/ directory
- POST requests to /wp-admin/admin-ajax.php with 'action=external_image_replace_get_posts'
- Files with double extensions (.php.jpg, .php.png)
Network Indicators:
- HTTP POST requests with file uploads containing executable content
- Traffic to unexpected PHP files in upload directories
SIEM Query:
source="web_server" AND (uri_path="*admin-ajax.php*" AND post_data="*external_image_replace*" AND post_data="*upload*" AND post_data="*.php*")