CVE-2020-35284
📋 TL;DR
CVE-2020-35284 is a path traversal vulnerability in FlamingoIM that allows attackers to read arbitrary files on the server. This occurs because file-transfer requests use client-side MD5 computations that can be reverse-engineered from the open-source code. Anyone running FlamingoIM through version 2020-09-29 is affected.
💻 Affected Systems
- Flamingo (FlamingoIM)
📦 What is this software?
Flamingoim by Flamingoim Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through reading sensitive files like configuration files, SSH keys, or database credentials, potentially leading to lateral movement.
Likely Case
Unauthorized access to sensitive server files containing configuration data, user information, or system files.
If Mitigated
Limited impact if proper file permissions restrict access to sensitive files and network segmentation limits exposure.
🎯 Exploit Status
Exploitation is straightforward due to available source code and simple path traversal technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 2020-09-29
Vendor Advisory: https://github.com/balloonwj/flamingo/issues/48
Restart Required: Yes
Instructions:
1. Update FlamingoIM to the latest version after 2020-09-29. 2. Restart the FlamingoIM service. 3. Verify the fix by testing file transfer functionality.
🔧 Temporary Workarounds
Disable file transfer feature
allTemporarily disable the vulnerable file transfer functionality until patching is possible.
Modify FlamingoIM configuration to disable file transfers
Implement network restrictions
allRestrict access to FlamingoIM service to trusted networks only.
Configure firewall rules to limit FlamingoIM port access
🧯 If You Can't Patch
- Implement strict file system permissions to limit what files FlamingoIM can access
- Deploy network segmentation to isolate FlamingoIM servers from sensitive systems
🔍 How to Verify
Check if Vulnerable:
Check if FlamingoIM version is 2020-09-29 or earlier by examining version information in the application or configuration files.Check Version:
Check FlamingoIM configuration files or application logs for version informationVerify Fix Applied:
Verify the version is newer than 2020-09-29 and test that path traversal attempts in file transfers are properly blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns in FlamingoIM logs
- Multiple failed file transfer attempts with path traversal patterns
Network Indicators:
- Unusual file transfer requests containing '../' sequences
- Requests to unexpected file paths
SIEM Query:
source="flamingo.log" AND ("../" OR "..\\" OR path_traversal)