CVE-2025-43818
📋 TL;DR
A cross-site scripting (XSS) vulnerability in Liferay's Calendar widget allows attackers to inject malicious scripts or HTML via the Calendar Name field. This affects Liferay Portal 7.4.3.35-7.4.3.110 and multiple Liferay DXP versions. Attackers could execute arbitrary code in users' browsers when they view a malicious calendar entry.
💻 Affected Systems
- Liferay Portal
- Liferay DXP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, redirect to malicious sites, or install malware on user systems.
Likely Case
Session hijacking, credential theft, or defacement of calendar pages through script injection.
If Mitigated
Limited impact with proper input validation, output encoding, and Content Security Policy (CSP) headers in place.
🎯 Exploit Status
Requires ability to create or modify calendar entries. Could be exploited through social engineering or compromised accounts.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Liferay Portal 7.4.3.111+, Liferay DXP 2023.Q4.5+, 2023.Q3.7+, 7.4 update 93+, 7.3 update 37+
Vendor Advisory: https://liferay.dev/portal/security/known-vulnerabilities/-/asset_publisher/jekt/content/CVE-2025-43818
Restart Required: No
Instructions:
1. Backup your Liferay instance. 2. Apply the appropriate patch from Liferay's customer portal. 3. Clear cache and verify the fix.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize Calendar Name field inputs
Implement custom hook or filter to strip/escape HTML/script tags from calendar name submissions
Content Security Policy
allImplement strict CSP headers to prevent script execution
Add 'Content-Security-Policy: script-src 'self'' header to web server configuration
🧯 If You Can't Patch
- Disable or restrict Calendar widget access to trusted users only
- Implement web application firewall (WAF) rules to block XSS payloads in calendar parameters
🔍 How to Verify
Check if Vulnerable:
Test by attempting to inject <script>alert('XSS')</script> into Calendar Name field and check if script executesCheck Version:
Check Liferay Control Panel → Server Administration → Properties → liferay.versionVerify Fix Applied:
Attempt same XSS payload after patch - script should be properly escaped/not execute📡 Detection & Monitoring
Log Indicators:
- Unusual calendar creation/modification patterns
- Requests with script tags or encoded payloads in calendar parameters
Network Indicators:
- HTTP requests containing script tags in POST parameters for calendar endpoints
SIEM Query:
web_requests WHERE url_path CONTAINS '/calendar' AND (request_body CONTAINS '<script' OR request_body CONTAINS 'javascript:')