CVE-2025-11829
📋 TL;DR
The Five9 Live Chat WordPress plugin has a stored XSS vulnerability that allows authenticated users with contributor-level access or higher to inject malicious scripts into web pages. These scripts execute when other users view the compromised pages, potentially stealing credentials or performing unauthorized actions. This affects all WordPress sites using the plugin version 1.1.2 or earlier.
💻 Affected Systems
- Five9 Live Chat 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 steal administrator credentials, take over the WordPress site, install backdoors, deface the site, or redirect visitors to malicious sites.
Likely Case
Attackers with contributor access inject malicious scripts to steal session cookies or user credentials, potentially compromising user accounts and site integrity.
If Mitigated
With proper user access controls and content security policies, the impact is limited to potential data leakage from users viewing compromised pages.
🎯 Exploit Status
Exploitation requires authenticated access (contributor role or higher) and knowledge of WordPress shortcode usage.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1.3 or later
Vendor Advisory: https://plugins.trac.wordpress.org/browser/five9/tags/1.1.3/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Five9 Live Chat' and click 'Update Now'. 4. Verify the plugin version is 1.1.3 or higher.
🔧 Temporary Workarounds
Remove Contributor Shortcode Access
allPrevent contributors from using the [five9-chat] shortcode by modifying user capabilities or using a plugin to restrict shortcode usage.
Content Security Policy
allImplement a strict Content Security Policy to block inline script execution and restrict script sources.
Add to .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
Or add to WordPress theme functions.php: header("Content-Security-Policy: default-src 'self'; script-src 'self'");
🧯 If You Can't Patch
- Disable the Five9 Live Chat plugin completely until patched.
- Restrict user roles to only trusted administrators and editors, removing contributor access.
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins → Five9 Live Chat version. If version is 1.1.2 or lower, you are vulnerable.Check Version:
wp plugin list --name=five9 --field=version (if WP-CLI installed) or check WordPress admin plugins page.Verify Fix Applied:
After updating, verify the plugin version shows 1.1.3 or higher in the WordPress plugins list.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to WordPress admin-ajax.php or admin-post.php containing 'five9-chat' or 'toolbar' parameters
- Multiple failed login attempts followed by successful contributor-level login
Network Indicators:
- Unexpected JavaScript payloads in HTTP responses containing 'five9-chat' or 'toolbar' attributes
SIEM Query:
source="wordpress_logs" AND ("five9-chat" OR "toolbar") AND (POST OR PUT)