CVE-2023-53886
📋 TL;DR
Xlight FTP Server 3.9.3.6 contains a stack buffer overflow vulnerability in the 'Execute Program' configuration that allows attackers to crash the application by inserting 294 characters. This affects administrators who have configured or can access the Execute Program feature, potentially causing denial of service.
💻 Affected Systems
- Xlight FTP Server
📦 What is this software?
Xlight Ftp Server by Xlightftpd
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the overflow can be controlled to execute arbitrary code.
Likely Case
Application crash causing denial of service, disrupting FTP services.
If Mitigated
Limited impact if Execute Program feature is disabled or access is restricted.
🎯 Exploit Status
Exploit requires access to Execute Program configuration; public proof-of-concept demonstrates crash.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.xlightftpd.com/
Restart Required: No
Instructions:
Check vendor website for updates; no official patch confirmed as of analysis.
🔧 Temporary Workarounds
Disable Execute Program Feature
windowsRemove or restrict access to the Execute Program configuration to prevent exploitation.
Navigate to Xlight FTP Server settings > Security > Execute Program and disable or remove entries.
🧯 If You Can't Patch
- Restrict network access to Xlight FTP Server to trusted IPs only.
- Monitor logs for unusual activity in Execute Program configuration changes.
🔍 How to Verify
Check if Vulnerable:
Check if Xlight FTP Server version is 3.9.3.6 and Execute Program configuration is accessible.Check Version:
Open Xlight FTP Server GUI and check Help > About for version.Verify Fix Applied:
Verify version is updated beyond 3.9.3.6 or Execute Program feature is disabled.📡 Detection & Monitoring
Log Indicators:
- Log entries showing application crashes or errors related to Execute Program configuration.
Network Indicators:
- Unusual FTP traffic patterns or connection attempts to Execute Program endpoints.
SIEM Query:
Search for 'Xlight FTP Server crash' or 'Execute Program' in application logs.