CVE-2023-51414
📋 TL;DR
This CVE describes an unauthenticated PHP object injection vulnerability in the EnvíaloSimple WordPress plugin. Attackers can exploit deserialization of untrusted data to execute arbitrary code on affected WordPress sites. All WordPress installations using EnvíaloSimple versions up to 2.1 are vulnerable.
💻 Affected Systems
- EnvialoSimple: Email Marketing y Newsletters WordPress plugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing remote code execution, data theft, site defacement, and backdoor installation leading to persistent access.
Likely Case
Remote code execution leading to website takeover, malware injection, credential theft, and unauthorized administrative access.
If Mitigated
Attack blocked at WAF level or prevented by plugin deactivation, limiting impact to potential DoS if exploitation attempts occur.
🎯 Exploit Status
Exploitation requires no authentication and proof-of-concept code is publicly available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find EnvíaloSimple plugin. 4. Click 'Update Now' if update available. 5. If no update available, deactivate and delete plugin immediately.
🔧 Temporary Workarounds
Immediate Plugin Deactivation
allDisable the vulnerable plugin to prevent exploitation while planning permanent fix.
wp plugin deactivate envialosimple-email-marketing-y-newsletters-gratis
WAF Rule Implementation
allBlock malicious deserialization attempts at web application firewall level.
Add rule to block requests containing suspicious serialized PHP object patterns
🧯 If You Can't Patch
- Immediately deactivate and remove the EnvíaloSimple plugin from all WordPress installations
- Implement strict WAF rules to block PHP object injection patterns and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → EnvíaloSimple version. If version is 2.1 or earlier, system is vulnerable.Check Version:
wp plugin get envialosimple-email-marketing-y-newsletters-gratis --field=versionVerify Fix Applied:
Verify plugin version is 2.2 or later in WordPress admin panel and ensure plugin is active without errors.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to WordPress endpoints, PHP error logs showing unserialize() warnings, unexpected file creations in wp-content/uploads
Network Indicators:
- HTTP requests containing serialized PHP object patterns (O: followed by numbers), unusual outbound connections from WordPress server
SIEM Query:
source="wordpress.log" AND ("unserialize" OR "O:" OR "envialosimple") AND status=200🔗 References
- https://patchstack.com/database/vulnerability/envialosimple-email-marketing-y-newsletters-gratis/wordpress-envialosimple-plugin-2-1-unauthenticated-php-object-injection-vulnerability?_s_id=cve
- https://patchstack.com/database/vulnerability/envialosimple-email-marketing-y-newsletters-gratis/wordpress-envialosimple-plugin-2-1-unauthenticated-php-object-injection-vulnerability?_s_id=cve
