CVE-2025-22528
📋 TL;DR
This stored cross-site scripting (XSS) vulnerability in the Huurkalender WP WordPress plugin allows attackers to inject malicious scripts into web pages. When users view affected pages, the scripts execute in their browsers, potentially stealing credentials or performing unauthorized actions. All WordPress sites using Huurkalender WP plugin versions up to 1.5.6 are affected.
💻 Affected Systems
- Huurkalender WP 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 session cookies, take over WordPress sites, deface websites, or redirect visitors to malicious sites, potentially compromising all site data and user information.
Likely Case
Attackers inject malicious JavaScript that steals user session cookies or credentials when users visit compromised pages, leading to account takeover and unauthorized access.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before reaching users, preventing execution and limiting impact to data display issues.
🎯 Exploit Status
Stored XSS vulnerabilities are commonly exploited. While no public PoC is confirmed, the vulnerability type suggests exploitation is straightforward for attackers with basic web security knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.7 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find Huurkalender WP plugin. 4. Click 'Update Now' if update available. 5. If no update available, deactivate and delete plugin, then install fresh version 1.5.7+ from WordPress repository.
🔧 Temporary Workarounds
Disable Plugin
allTemporarily disable the vulnerable plugin until patched version is available
wp plugin deactivate huurkalender-wp
Content Security Policy
allImplement CSP headers to restrict script execution
Add to .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
Add to wp-config.php: 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 plugin settings
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin > Plugins > Installed Plugins for Huurkalender WP version. If version is 1.5.6 or lower, system is vulnerable.Check Version:
wp plugin get huurkalender-wp --field=versionVerify Fix Applied:
After update, verify plugin version shows 1.5.7 or higher in WordPress admin plugins page.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to plugin endpoints with script tags
- Multiple failed login attempts following plugin page visits
- Unexpected JavaScript in database entries related to plugin
Network Indicators:
- Outbound connections to suspicious domains from WordPress site
- Unusual traffic patterns to plugin-specific URLs
SIEM Query:
source="wordpress.log" AND ("huurkalender" OR "wp-content/plugins/huurkalender-wp") AND ("<script>" OR "javascript:" OR "onload=" OR "onerror=")