CVE-2025-58386
📋 TL;DR
This vulnerability allows a Power User in Terminalfour to bypass authorization checks and escalate privileges for other accounts. By intercepting and modifying the userLevel parameter, they can assign Administrator roles to lower-privileged accounts and change passwords, effectively taking control. This affects Terminalfour versions 8 through 8.4.1.1.
💻 Affected Systems
- Terminalfour
📦 What is this software?
Terminalfour by Terminalfour
⚠️ Risk & Real-World Impact
Worst Case
A malicious Power User could elevate all user accounts to Administrator, change their passwords, and gain complete control over the Terminalfour system, potentially leading to data theft, system compromise, or service disruption.
Likely Case
A Power User with malicious intent or compromised credentials escalates privileges for specific accounts they target, gaining administrative access to manipulate content, user management, and system settings.
If Mitigated
With proper network segmentation and monitoring, impact is limited to unauthorized privilege changes that can be detected and rolled back before widespread damage occurs.
🎯 Exploit Status
Exploitation requires authenticated Power User access; manipulation involves intercepting and modifying HTTP requests, which is straightforward with tools like Burp Suite or proxy interceptors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.4.1.2 or later
Vendor Advisory: https://docs.terminalfour.com/release-notes/security-notices/cve-2025-58386/
Restart Required: Yes
Instructions:
1. Backup your Terminalfour instance. 2. Download and apply the patch from Terminalfour's official update channel. 3. Restart the Terminalfour service. 4. Verify the fix by testing user management functions.
🔧 Temporary Workarounds
Restrict Power User Access
allTemporarily limit or revoke Power User privileges to reduce attack surface until patching is complete.
Network Segmentation
allIsolate Terminalfour management interfaces from general user networks to prevent interception of requests.
🧯 If You Can't Patch
- Monitor user management logs for unauthorized privilege changes and implement strict access controls for Power Users.
- Use web application firewalls (WAFs) to block or alert on suspicious modifications to userLevel parameters in HTTP requests.
🔍 How to Verify
Check if Vulnerable:
Check the Terminalfour version in the admin interface or configuration files; if it's between 8 and 8.4.1.1, the system is vulnerable.Check Version:
Check the Terminalfour admin panel or review installation logs for version information.Verify Fix Applied:
After patching, attempt to replicate the exploit as a Power User; successful privilege escalation should be blocked, and the system should log authorization failures.📡 Detection & Monitoring
Log Indicators:
- Unauthorized modifications to userLevel parameter in user management logs
- Sudden privilege escalation events for multiple accounts
- Failed authorization attempts in server logs
Network Indicators:
- HTTP POST requests to user management endpoints with modified userLevel parameters
- Unusual traffic patterns from Power User accounts
SIEM Query:
source="terminalfour_logs" AND (event="user_update" AND parameter="userLevel" AND old_value!=new_value) | stats count by user