CVE-2025-47811: Wing FTP Server Privilege Escalation

CVE-2025-47811 Overview

CVE-2025-47811 is a privilege escalation vulnerability affecting Wing FTP Server through version 7.4.4. The administrative web interface, which listens by default on port 5466, runs with root or SYSTEM privileges. The web application provides legitimate mechanisms to execute arbitrary system commands through the web console or task scheduler, and these commands are automatically executed in the highest possible privilege context. This design flaw allows administrative users of the web interface—who are not necessarily system administrators—to escalate their privileges and execute commands with root/SYSTEM permissions.

Critical Impact

Web application administrators can execute arbitrary system commands with root/SYSTEM privileges, potentially leading to complete system compromise.

Affected Products

• Wing FTP Server versions through 7.4.4
• Installations with administrative web interface enabled on port 5466
• Windows (SYSTEM) and Linux/Unix (root) deployments

Discovery Timeline

• 2025-07-10 - CVE-2025-47811 published to NVD
• 2025-07-17 - Last updated in NVD database

Technical Details for CVE-2025-47811

Vulnerability Analysis

The vulnerability stems from an insecure default configuration where the Wing FTP Server's administrative web interface runs with elevated privileges. The application provides built-in functionality for executing system commands through the web console and task scheduler features. When an attacker gains access to the administrative web interface, they can leverage these legitimate features to execute arbitrary commands with root (on Unix/Linux) or SYSTEM (on Windows) privileges.

This represents a vertical privilege escalation scenario where web application administrators—a role that should be logically separated from operating system administrators—can gain full system-level access. The vendor has reportedly stated this behavior is intended and will be maintained, which increases the long-term risk for organizations using this product.

The vulnerability is related to CVE-2025-47812, which can be leveraged to gain the initial privileged application role if an attacker does not already have administrative access.

Root Cause

The root cause is classified as CWE-267 (Privilege Defined With Unsafe Actions). The Wing FTP Server administrative web interface executes with unnecessarily elevated privileges (root/SYSTEM) by default, and the application design allows web administrators to trigger system command execution. This violates the principle of least privilege, as the administrative web interface should run with minimal permissions necessary for its function, and command execution should be restricted or run with reduced privileges.

Attack Vector

The attack vector is network-based, requiring authenticated access to the administrative web interface. An attacker with administrative credentials to the Wing FTP web interface can:

1. Access the administrative panel on port 5466
2. Navigate to the web console or task scheduler functionality
3. Execute arbitrary system commands that run with root/SYSTEM privileges
4. Achieve complete system compromise without requiring OS-level administrative access

The attack can be executed remotely over the network, requires high privileges (administrative web access), but has low complexity and requires no user interaction. The scope is changed, meaning the vulnerability can affect resources beyond the vulnerable component's security scope.

Detection Methods for CVE-2025-47811

Indicators of Compromise

• Unusual command execution events originating from the Wing FTP Server process
• Unexpected processes spawned as child processes of the Wing FTP Server service
• Administrative logins to port 5466 from unexpected IP addresses or at unusual times
• Task scheduler entries created with suspicious command payloads

Detection Strategies

• Monitor Windows Event Logs or Unix syslog for process creation events where the parent process is the Wing FTP Server service
• Implement network monitoring for connections to port 5466 from non-authorized IP ranges
• Review Wing FTP Server audit logs for web console command execution and task scheduler modifications
• Deploy endpoint detection and response (EDR) solutions to identify suspicious command execution patterns

Monitoring Recommendations

• Enable detailed audit logging in Wing FTP Server for administrative actions
• Configure SIEM alerts for command execution through the web console
• Implement privileged access monitoring for the Wing FTP administrative interface
• Monitor for lateral movement following any suspicious activity from the FTP server host

How to Mitigate CVE-2025-47811

Immediate Actions Required

• Restrict network access to the administrative web interface (port 5466) using firewall rules
• Limit administrative web interface access to trusted IP addresses only
• Review and audit all accounts with administrative access to the Wing FTP web interface
• Consider running Wing FTP Server under a dedicated service account with reduced privileges where possible

Patch Information

As of the last update on 2025-07-17, no vendor patch is available for this vulnerability. The vendor has reportedly stated this behavior is intentional and will be maintained. Organizations should implement compensating controls until the vendor reconsiders this design decision. For additional technical context, see the RCE Security CVE-2025-47812 Analysis which discusses related vulnerabilities.

Workarounds

• Implement strict network segmentation to isolate the Wing FTP Server administrative interface from untrusted networks
• Deploy multi-factor authentication in front of the administrative interface using a reverse proxy or VPN
• Consider alternative FTP server solutions that implement proper privilege separation
• Disable web console and task scheduler features if they are not operationally required

# Example firewall configuration to restrict administrative interface access
# Only allow administrative access from trusted management network
iptables -A INPUT -p tcp --dport 5466 -s 10.0.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 5466 -j DROP