CVE-2020-27832
📋 TL;DR
CVE-2020-27832 is a persistent cross-site scripting (XSS) vulnerability in Red Hat Quay that allows attackers to inject malicious scripts into repository notifications. When exploited, this can trick authenticated users into performing unauthorized actions, potentially compromising their accounts. Organizations running vulnerable versions of Red Hat Quay are affected.
💻 Affected Systems
- Red Hat Quay
📦 What is this software?
Quay by Redhat
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, take over Quay instances, compromise container registries, and potentially pivot to downstream systems using stolen credentials.
Likely Case
Attackers steal session cookies or authentication tokens from authenticated users, leading to unauthorized access to container repositories and potential data exfiltration.
If Mitigated
With proper input validation and output encoding, the attack surface is limited to authenticated users only, reducing the blast radius.
🎯 Exploit Status
Exploitation requires user interaction (clicking on malicious notification) but uses standard XSS techniques that are well-understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Red Hat Quay 3.5.1 and later
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2020-27832
Restart Required: Yes
Instructions:
1. Backup your Quay configuration and database. 2. Update to Red Hat Quay 3.5.1 or later using your package manager. 3. Restart the Quay service. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Repository Notifications
linuxTemporarily disable repository notification features to prevent exploitation
Modify Quay configuration to disable notification features
Implement Content Security Policy
allAdd CSP headers to restrict script execution
Add 'Content-Security-Policy' headers to Quay web server configuration
🧯 If You Can't Patch
- Implement strict input validation and output encoding for all user-controlled data in notifications
- Use web application firewall (WAF) rules to block XSS payloads in notification parameters
🔍 How to Verify
Check if Vulnerable:
Check Quay version: if running version earlier than 3.5.1, the system is vulnerableCheck Version:
docker exec quay-registry quay --versionVerify Fix Applied:
Verify Quay version is 3.5.1 or later and test notification functionality with XSS payloads📡 Detection & Monitoring
Log Indicators:
- Unusual notification creation patterns
- JavaScript payloads in notification parameters
- Multiple failed login attempts following notification views
Network Indicators:
- Suspicious outbound connections after notification access
- Unexplained data exfiltration patterns
SIEM Query:
source="quay" AND (notification_created OR notification_viewed) AND (javascript: OR <script> OR onerror=)