CVE-2025-64325
📋 TL;DR
This vulnerability allows an attacker to inject malicious content into the Emby Server admin dashboard by manipulating the X-Emby-Client header during authentication. The injected content appears unsanitized in the devices section, potentially enabling cross-site scripting attacks. All Emby Server instances running vulnerable versions are affected.
💻 Affected Systems
- Emby Server
📦 What is this software?
Emby by Emby
⚠️ Risk & Real-World Impact
Worst Case
An attacker could execute arbitrary JavaScript in the admin dashboard context, potentially stealing admin credentials, performing actions as the admin, or compromising the server.
Likely Case
Attackers could inject malicious scripts that steal session cookies or credentials when administrators view the devices section, leading to account takeover.
If Mitigated
With proper network segmentation and admin access controls, impact is limited to the admin interface only.
🎯 Exploit Status
Exploitation requires sending a manipulated authentication request, but no authentication bypass is needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.8.1.0 or 4.9.0.0-beta
Vendor Advisory: https://github.com/EmbySupport/Emby.Security/security/advisories/GHSA-2gwc-988r-2r7x
Restart Required: Yes
Instructions:
1. Download Emby Server version 4.8.1.0 or later from official sources. 2. Stop the Emby Server service. 3. Install the updated version. 4. Restart the Emby Server service.
🔧 Temporary Workarounds
Restrict Admin Dashboard Access
allLimit access to the Emby admin dashboard to trusted IP addresses only using firewall rules or reverse proxy configurations.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Emby Server from untrusted networks
- Monitor authentication logs for unusual X-Emby-Client header values
🔍 How to Verify
Check if Vulnerable:
Check Emby Server version in admin dashboard under Dashboard > Server > About. If version is below 4.8.1.0 and not 4.9.0.0-beta or higher, it's vulnerable.Check Version:
On Linux: cat /opt/emby-server/system/version.txt || On Windows: Check Emby Server installation directory for version fileVerify Fix Applied:
After patching, verify version shows 4.8.1.0 or higher in the admin dashboard.📡 Detection & Monitoring
Log Indicators:
- Unusual X-Emby-Client header values in authentication logs
- Multiple authentication attempts with varying client identifiers
Network Indicators:
- HTTP requests to Emby Server with manipulated X-Emby-Client headers
SIEM Query:
source="emby" AND (http_user_agent CONTAINS "<script>" OR http_header_X-Emby-Client CONTAINS suspicious_patterns)