CVE-2025-46093: Critical Vulnerability in LiquidFiles Allowing Root Access via FTP SITE CHMOD

Overview

In this post, we will explore the details of a critical security vulnerability, known as CVE-2025-46093, that affects versions of LiquidFiles prior to 4.1.2. This vulnerability enables FTPDrop users to gain root-level access and execute arbitrary code on affected systems by leveraging the Actionscript feature and sudoers configuration. Given the severity and potential ramifications, understanding this vulnerability is critical for IT security professionals, system administrators, and developers who work with or support LiquidFiles systems.

Vulnerability Summary

CVE ID: CVE-2025-46093
Severity: Critical (CVSS 9.9)
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

LiquidFiles | Before 4.1.2

How the Exploit Works

The vulnerability stems from LiquidFiles’ support for FTP SITE CHMOD for mode 6777 (setuid and setgid). This allows FTPDrop users to manipulate file permissions, ultimately enabling them to execute arbitrary code as root. They achieve this by exploiting the Actionscript feature and the sudoers configuration. Given the power associated with root-level access, successful exploitation of this vulnerability could lead to full system compromise, including unauthorized data access, data modification, or service disruption.

Conceptual Example Code

Here’s a conceptual example of how an attacker might exploit this vulnerability:

# Log in to the FTP server
ftp target.example.com
# Change to the directory containing the file to exploit
cd /path/to/target/directory
# Change the mode of the file to 6777 using SITE CHMOD
SITE CHMOD 6777 targetfile
# Execute the script as root
echo "os.execute('sh')" > exploit.as && gcc -o exploit exploit.as
# Use sudo to run the exploit script
sudo ./exploit

This example demonstrates how an attacker could use FTP SITE CHMOD to change file permissions, compile an exploit script, and then execute this script as root. This is just a conceptual demonstration; the actual exploitation would involve more complex and specific steps depending on the exact system configuration and the attacker’s objectives.

Mitigation Guidance

To remediate this vulnerability, users are advised to update their LiquidFiles software to version 4.1.2 or later, which contains a patch for this security issue. If immediate patching is not feasible, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. However, these measures only provide a stopgap solution and do not fully resolve the vulnerability. As such, patching should be carried out as soon as possible to fully protect systems from potential exploitation.