CVE-2025-47812 Overview
In Wing FTP Server before version 7.4.4, the user and admin web interfaces mishandle \0 bytes, which allows the injection of arbitrary Lua code into user session files. This enables execution of arbitrary system commands with the privileges of the FTP service (root or SYSTEM by default). This is a remote code execution vulnerability, providing a means for complete server compromise, and is exploitable via anonymous FTP accounts.
Critical Impact
This vulnerability allows full system compromise via arbitrary code execution with root or SYSTEM privileges.
Affected Products
- Wing FTP Server (all versions before 7.4.4)
Discovery Timeline
- 2025-07-10 - CVE CVE-2025-47812 published to NVD
- 2025-11-05 - Last updated in NVD database
Technical Details for CVE-2025-47812
Vulnerability Analysis
The flaw results from improper handling of null byte (\0) inputs by the user and admin web interfaces. This mishandling allows attackers to inject Lua scripts into session files, facilitating remote command execution with elevated privileges.
Root Cause
The vulnerability is rooted in the web interfaces' failure to sanitize inputs that include embedded null bytes, allowing code injection into session management files processed by the FTP server.
Attack Vector
This is an externally exploitable vulnerability via the network, accessible through both authenticated and unauthenticated channels, including anonymous FTP access.
-- Example exploitation code (sanitized)
local payload = "os.execute('whoami')"
local injected_session_file = "|\0" .. payload .. "\0|"
Detection Methods for CVE-2025-47812
Indicators of Compromise
- Unexpected system command executions via init.lua
- Modification of FTP user session files
- Unusual log entries or connections to the FTP service
Detection Strategies
Employ file integrity monitoring tools to detect unauthorized changes to session files and init.lua. Leverage intrusion detection systems (IDS) to flag suspicious activity involving \0 byte patterns in FTP communication.
Monitoring Recommendations
Regularly audit FTP server logs for irregular command executions and session file modifications. Utilize network traffic analysis to identify patterns consistent with exploitation attempts.
How to Mitigate CVE-2025-47812
Immediate Actions Required
- Disable anonymous FTP access if not necessary
- Restrict FTP access to trusted IP ranges
- Implement least privilege principles and review service account permissions
Patch Information
A security patch has been released by the vendor, updating Wing FTP Server to version 7.4.4. It is crucial to apply this patch immediately to mitigate the vulnerability.
Workarounds
As an interim measure, administrators can disable the web management interface or restrict access using firewall rules to trusted IPs only.
# Configuration example
iptables -I INPUT -p tcp -s <trusted_ip> --dport 21 -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
