CVE-2023-49858
📋 TL;DR
This CVE describes a missing authorization vulnerability in the Custom Login WordPress plugin that allows attackers to bypass access controls. It affects all WordPress sites running Custom Login plugin versions up to 4.1.0, potentially exposing sensitive administrative functions to unauthorized users.
💻 Affected Systems
- Custom Login 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
Attackers could gain administrative access to WordPress sites, modify user accounts, install malicious plugins/themes, or deface websites.
Likely Case
Unauthorized users accessing restricted administrative functions, potentially modifying site settings or user permissions.
If Mitigated
Minimal impact with proper access controls, network segmentation, and security monitoring in place.
🎯 Exploit Status
Exploitation requires some level of access but doesn't require authentication to WordPress admin. The vulnerability is in access control mechanisms, making exploitation straightforward once identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.1.1 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find Custom Login plugin. 4. Click 'Update Now' if available. 5. Alternatively, download latest version from WordPress repository and manually update.
🔧 Temporary Workarounds
Disable Custom Login Plugin
allTemporarily disable the vulnerable plugin until patching is possible
wp plugin deactivate custom-login
Restrict Plugin Access via .htaccess
linuxAdd access restrictions to plugin directory
<FilesMatch "\.(php|inc)$">
Order Deny,Allow
Deny from all
</FilesMatch>
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block suspicious access patterns to Custom Login endpoints
- Enable detailed logging and monitoring for unauthorized access attempts to administrative functions
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins → Custom Login version. If version is 4.1.0 or earlier, you are vulnerable.Check Version:
wp plugin get custom-login --field=versionVerify Fix Applied:
Verify Custom Login plugin version is 4.1.1 or later in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to /wp-content/plugins/custom-login/ endpoints
- Multiple failed authorization attempts followed by successful access to restricted functions
Network Indicators:
- Unusual HTTP requests to Custom Login plugin endpoints from unauthorized IPs
- POST requests to administrative functions without proper authentication headers
SIEM Query:
source="wordpress.log" AND (uri_path="/wp-content/plugins/custom-login/*" OR plugin="custom-login") AND (response_code=200 OR response_code=302) AND user_agent NOT IN ("admin_user_agents")