CVE-2023-27616
📋 TL;DR
Unauthenticated stored cross-site scripting (XSS) vulnerability in the RSVPMaker WordPress plugin allows attackers to inject malicious scripts that execute when users view affected pages. This affects WordPress sites running RSVPMaker plugin version 10.6.6 or earlier. The vulnerability enables session hijacking, credential theft, and website defacement.
💻 Affected Systems
- WordPress RSVPMaker plugin
📦 What is this software?
Rsvpmaker by Carrcommunications
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator credentials, take over the WordPress site, install backdoors, and compromise all user data.
Likely Case
Attackers hijack user sessions, redirect visitors to malicious sites, or deface website content.
If Mitigated
With proper input validation and output encoding, the attack fails to execute malicious scripts.
🎯 Exploit Status
XSS vulnerabilities are commonly exploited and require minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.6.7 or later
Vendor Advisory: https://patchstack.com/database/vulnerability/rsvpmaker/wordpress-rsvpmaker-plugin-10-6-4-cross-site-scripting-xss-vulnerability-2?_s_id=cve
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find RSVPMaker and click 'Update Now'. 4. Verify version is 10.6.7 or higher.
🔧 Temporary Workarounds
Disable RSVPMaker plugin
allTemporarily disable the vulnerable plugin until patched.
wp plugin deactivate rsvpmaker
Implement Content Security Policy
allAdd CSP headers to restrict script execution sources.
Add to .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
Add to nginx config: add_header Content-Security-Policy "default-src 'self'; script-src 'self'";
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block XSS payloads.
- Disable user input fields that accept HTML/JavaScript in RSVPMaker settings.
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel > Plugins > Installed Plugins for RSVPMaker version.Check Version:
wp plugin get rsvpmaker --field=versionVerify Fix Applied:
Confirm RSVPMaker version is 10.6.7 or higher in WordPress admin.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to RSVPMaker endpoints with script tags
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests containing <script> tags to RSVPMaker URLs
- Unexpected JavaScript payloads in form submissions
SIEM Query:
source="web_server.log" AND ("rsvpmaker" AND ("<script>" OR "javascript:"))