CVE-2020-15273
📋 TL;DR
baserCMS versions 4.0.0 through 4.4.0 contain a cross-site scripting vulnerability in management interface components. Attackers with administrative access can inject malicious JavaScript into feed settings, widget areas, sub-site registrations, and category registrations, potentially compromising other administrators' sessions. This affects all baserCMS installations with vulnerable versions and administrative users.
💻 Affected Systems
- baserCMS
📦 What is this software?
Basercms by Basercms
⚠️ Risk & Real-World Impact
Worst Case
Administrator account takeover leading to complete system compromise, data theft, or website defacement through stored XSS payloads.
Likely Case
Session hijacking of administrative users, credential theft, or unauthorized administrative actions performed through injected scripts.
If Mitigated
Limited impact if proper input validation and output encoding are implemented, or if administrative access is strictly controlled.
🎯 Exploit Status
Exploitation requires administrative privileges. Attack vectors involve injecting JavaScript into specific management interface fields.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.4.1
Vendor Advisory: https://github.com/baserproject/basercms/security/advisories/GHSA-wpww-4jf4-4hx8
Restart Required: No
Instructions:
1. Backup your baserCMS installation and database. 2. Update baserCMS to version 4.4.1 or later via Composer: 'composer require baserproject/basercms:^4.4.1'. 3. Clear application cache if applicable.
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement additional input sanitization for the affected fields in custom code.
Content Security Policy
allImplement strict CSP headers to mitigate XSS impact.
🧯 If You Can't Patch
- Restrict administrative access to trusted users only and implement multi-factor authentication.
- Monitor and audit administrative actions in the affected components for suspicious input patterns.
🔍 How to Verify
Check if Vulnerable:
Check baserCMS version in administration panel or via 'composer show baserproject/basercms' command.Check Version:
composer show baserproject/basercms | grep versionsVerify Fix Applied:
Verify version is 4.4.1 or higher and test affected components for proper input sanitization.📡 Detection & Monitoring
Log Indicators:
- Unusual administrative activity in feed settings, widget areas, or category management
- JavaScript patterns in administrative input fields
Network Indicators:
- Unexpected script tags in administrative interface responses
SIEM Query:
source="basercms" AND (event="admin_action" AND (field="feed_settings" OR field="widget_area" OR field="subsite" OR field="category") AND input CONTAINS "<script>")🔗 References
- https://github.com/baserproject/basercms/commit/b70474ef9dcee6ad8826360884625dc7ca9041a1
- https://github.com/baserproject/basercms/security/advisories/GHSA-wpww-4jf4-4hx8
- https://packagist.org/packages/baserproject/basercms
- https://github.com/baserproject/basercms/commit/b70474ef9dcee6ad8826360884625dc7ca9041a1
- https://github.com/baserproject/basercms/security/advisories/GHSA-wpww-4jf4-4hx8
- https://packagist.org/packages/baserproject/basercms
