CVE-2023-48745
📋 TL;DR
This vulnerability allows attackers to bypass CAPTCHA protection in WebFactory Ltd's Captcha Code WordPress plugin by making excessive authentication attempts without proper rate limiting. It affects WordPress sites using Captcha Code plugin versions up to 2.9, potentially enabling automated attacks on login forms and other protected areas.
💻 Affected Systems
- WebFactory Ltd Captcha Code 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 perform credential stuffing, brute force attacks, or automated form submissions to compromise user accounts, post spam content, or conduct other malicious activities that the CAPTCHA was designed to prevent.
Likely Case
Automated bots bypass CAPTCHA protection to perform brute force attacks on login forms, potentially compromising user accounts or administrator access.
If Mitigated
With proper rate limiting and monitoring, impact is limited to increased failed login attempts that can be detected and blocked.
🎯 Exploit Status
Exploitation involves sending repeated authentication attempts to bypass CAPTCHA validation, which is trivial for automated tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.10 or later
Vendor Advisory: https://patchstack.com/database/vulnerability/captcha-code-authentication/wordpress-captcha-code-plugin-2-8-captcha-bypass-vulnerability
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Captcha Code' plugin. 4. Click 'Update Now' if update available. 5. If no update available, deactivate and delete plugin, then install version 2.10+ from WordPress repository.
🔧 Temporary Workarounds
Implement Web Application Firewall (WAF) Rules
allConfigure WAF to rate limit authentication attempts and detect CAPTCHA bypass patterns
Use Alternative CAPTCHA Solution
allReplace vulnerable plugin with alternative CAPTCHA plugin like reCAPTCHA or hCaptcha
🧯 If You Can't Patch
- Deactivate and remove the Captcha Code plugin immediately
- Implement server-side rate limiting for all authentication endpoints
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins → Captcha Code version. If version is 2.9 or earlier, you are vulnerable.Check Version:
wp plugin list --name=captcha-code --field=version (if WP-CLI installed)Verify Fix Applied:
After updating, verify plugin version shows 2.10 or later in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts from same IP in short timeframe
- Successful logins after many failed attempts
- Unusual pattern of form submissions bypassing CAPTCHA
Network Indicators:
- High volume of POST requests to login endpoints
- Repeated authentication attempts with varying credentials
SIEM Query:
source="wordpress.log" AND ("wp-login.php" OR "xmlrpc.php") AND status=401 | stats count by src_ip | where count > 10