CVE-2025-58998
📋 TL;DR
This CVE describes a PHP object injection vulnerability in the s2Member WordPress plugin that allows attackers to execute arbitrary code by deserializing untrusted data. It affects all WordPress sites running s2Member versions up to and including 250701. Successful exploitation could lead to complete system compromise.
💻 Affected Systems
- WordPress s2Member 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
Remote code execution leading to complete server takeover, data exfiltration, and persistent backdoor installation.
Likely Case
Unauthenticated attackers gaining administrative access to WordPress, installing malware, or defacing websites.
If Mitigated
Limited impact if proper input validation and output encoding are implemented elsewhere in the application stack.
🎯 Exploit Status
Deserialization vulnerabilities are commonly exploited and weaponized quickly in WordPress ecosystems.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 250701
Vendor Advisory: https://patchstack.com/database/Wordpress/Plugin/s2member/vulnerability/wordpress-s2member-plugin-250701-php-object-injection-vulnerability?_s_id=cve
Restart Required: No
Instructions:
1. Log into WordPress admin panel
2. Navigate to Plugins → Installed Plugins
3. Find s2Member and click 'Update Now'
4. Verify update to version newer than 250701
5. Clear any caching plugins/CDN caches
🔧 Temporary Workarounds
Disable s2Member plugin
allTemporarily disable the vulnerable plugin until patched
wp plugin deactivate s2member
Web Application Firewall rule
allBlock deserialization attempts at WAF level
Add rule to block requests containing serialized PHP objects in parameters
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all user inputs
- Deploy web application firewall with rules targeting PHP object injection patterns
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → s2Member version. If version is 250701 or lower, you are vulnerable.Check Version:
wp plugin get s2member --field=versionVerify Fix Applied:
Verify s2Member plugin version is higher than 250701 in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to WordPress endpoints
- PHP unserialize() errors in logs
- Unexpected plugin file modifications
Network Indicators:
- HTTP requests containing serialized PHP objects (O: or a: in parameters)
- Traffic to known exploit patterns for s2Member
SIEM Query:
source="wordpress.log" AND ("unserialize" OR "s2member" OR "php object")