CVE-2025-67555
📋 TL;DR
This stored cross-site scripting (XSS) vulnerability in UseStrict's Calendly Embedder WordPress plugin allows attackers to inject malicious scripts that execute when other users view affected pages. WordPress site administrators and users who view pages containing the malicious embed are affected. The vulnerability exists in versions up to and including 1.1.7.2.
💻 Affected Systems
- UseStrict's Calendly Embedder (cal-embedder-lite)
⚠️ 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 session cookies, take over WordPress sites, redirect users to malicious sites, or deploy malware to visitors' browsers.
Likely Case
Attackers inject malicious JavaScript to steal user session cookies, potentially compromising WordPress admin accounts and defacing websites.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before execution, preventing any impact.
🎯 Exploit Status
Stored XSS vulnerabilities in WordPress plugins are commonly exploited. While no public PoC is confirmed, similar vulnerabilities are frequently weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 1.1.7.2
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'UseStrict's Calendly Embedder'. 4. Click 'Update Now' if available, or manually update to latest version. 5. Verify plugin is updated to version after 1.1.7.2.
🔧 Temporary Workarounds
Disable vulnerable plugin
allTemporarily disable the Calendly Embedder plugin until patched
wp plugin deactivate cal-embedder-lite
Implement WAF rules
allConfigure web application firewall to block XSS payloads targeting Calendly embed parameters
🧯 If You Can't Patch
- Remove or disable the Calendly Embedder plugin entirely
- Implement strict Content Security Policy (CSP) headers to restrict script execution
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins for 'UseStrict's Calendly Embedder' versionCheck Version:
wp plugin get cal-embedder-lite --field=versionVerify Fix Applied:
Verify plugin version is greater than 1.1.7.2 in WordPress admin panel📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to Calendly embed endpoints
- JavaScript payloads in plugin-related parameters
Network Indicators:
- Malicious script injections in Calendly embed parameters
- Unexpected external script loads from calendly embed pages
SIEM Query:
source="wordpress" AND (plugin="cal-embedder-lite" OR uri="*calendly*") AND (payload="<script>" OR payload="javascript:")