CVE-2020-35243
📋 TL;DR
CVE-2020-35243 is a SQL injection vulnerability in FlamingoIM's UserManager::updateUserInfoInDb function that allows attackers to execute arbitrary SQL commands. This affects all FlamingoIM installations through version 2020-09-29. Attackers could potentially access, modify, or delete database contents.
💻 Affected Systems
- Flamingo (FlamingoIM)
📦 What is this software?
Flamingo by Flamingo Project
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise leading to data theft, data destruction, authentication bypass, and potential remote code execution via database functions.
Likely Case
Unauthorized data access and modification, potentially exposing user credentials, messages, and sensitive information.
If Mitigated
Limited impact with proper input validation, parameterized queries, and database permission restrictions in place.
🎯 Exploit Status
SQL injection vulnerabilities are well-understood and easily weaponized. The GitHub issue shows proof of concept exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 2020-09-29
Vendor Advisory: https://github.com/balloonwj/flamingo/issues/47
Restart Required: Yes
Instructions:
1. Update FlamingoIM to version after 2020-09-29. 2. Replace vulnerable UserManager::updateUserInfoInDb function with parameterized queries. 3. Restart FlamingoIM service.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for all user inputs to the updateUserInfoInDb function
# Add input validation in source code before SQL execution
# Example: if (!isValidInput(userInput)) { return error; }
Database Permission Reduction
allLimit database user permissions to minimum required operations
# MySQL example: REVOKE ALL PRIVILEGES ON flamingo.* FROM 'flamingo_user'@'localhost';
# GRANT SELECT, INSERT, UPDATE ON flamingo.* TO 'flamingo_user'@'localhost';
🧯 If You Can't Patch
- Implement web application firewall (WAF) with SQL injection rules
- Isolate FlamingoIM server from sensitive networks and implement strict network access controls
🔍 How to Verify
Check if Vulnerable:
Check FlamingoIM version and verify if using UserManager::updateUserInfoInDb function without parameterized queriesCheck Version:
# Check FlamingoIM version in configuration or about dialogVerify Fix Applied:
Verify FlamingoIM version is after 2020-09-29 and inspect source code for parameterized queries in UserManager::updateUserInfoInDb📡 Detection & Monitoring
Log Indicators:
- Unusual SQL query patterns in database logs
- Multiple failed login attempts followed by SQL errors
- Unexpected database schema changes
Network Indicators:
- Unusual SQL syntax in HTTP POST parameters
- Multiple rapid requests to user update endpoints
- Database connection attempts from unexpected sources
SIEM Query:
source="flamingo.log" AND ("SQL" OR "database" OR "query") AND ("error" OR "exception" OR "injection")