CVE-2025-24472: Fortinet FortiProxy Auth Bypass Vulnerability

CVE-2025-24472 Overview

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS 7.0.0 through 7.0.16 and FortiProxy 7.2.0 through 7.2.12, 7.0.0 through 7.0.19 may allow a remote unauthenticated attacker with prior knowledge of upstream and downstream devices serial numbers to gain super-admin privileges on the downstream device, if the Security Fabric is enabled, via crafted CSF proxy requests.

Critical Impact
Remote attackers can gain super-admin access due to authentication bypass.

Affected Products

Fortinet FortiProxy 7.2.0 through 7.2.12
Fortinet FortiProxy 7.0.0 through 7.0.19
Fortinet FortiOS 7.0.0 through 7.0.16

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to fortinet
Not Available - CVE CVE-2025-24472 assigned
Not Available - fortinet releases security patch
2025-02-11 - CVE CVE-2025-24472 published to NVD
2025-10-24 - Last updated in NVD database

Technical Details for CVE-2025-24472

Vulnerability Analysis

The vulnerability resides in the Security Fabric component of FortiOS and FortiProxy. By exploiting crafted CSF proxy requests with knowledge of specific serial numbers, attackers bypass the usual authentication mechanisms, escalating their privileges to super-admin levels on targeted devices.

Root Cause

The core issue stems from improper validation within the CSF proxy requests, which allows access bypass when attackers supply valid serial numbers.

Attack Vector

Network-based attack utilizing specially crafted CSF proxy requests targeting improperly authenticated paths.

python

# Example exploitation code (sanitized)
def exploit(device_serial_numbers):
    for serial in device_serial_numbers:
        request = create_csf_request(serial)
        response = send_exploit(request)
        if check_success(response):
            print(f"Access granted for serial: {serial}")

# Simplified demonstration
exploit(['12345', '67890'])

Detection Methods for CVE-2025-24472

Indicators of Compromise

Unusual login activity from unauthorized IP addresses
Access granted logs without corresponding authentication requests
Changes in administration roles or settings

Detection Strategies

Monitor for CSF proxy requests that do not correspond to authenticated sessions. Deploy anomaly detection systems to flag irregular access patterns and audit logs for unauthorized privilege escalations.

Monitoring Recommendations

Utilize threat intelligence feeds to stay updated on potential exploits targeting FortiOS. Incorporate SentinelOne's behavioral tracking to detect unexpected admin-level actions on security devices.

How to Mitigate CVE-2025-24472

Immediate Actions Required

Disable Security Fabric until the patch is applied
Restrict network access to management interfaces
Implement strict logging and access monitoring

Patch Information

Fortinet has released patches for FortiOS and FortiProxy. It is critical to apply the latest updates as outlined in Fortinet's advisory.

Workarounds

As a temporary measure, block all CSF proxy communications until the system can be patched.

bash

# Configuration example
iptables -A INPUT -p tcp --dport 8888 -j DROP
# Make sure to replace '8888' with the actual port number used by CSF proxy