CVE-2020-28446
📋 TL;DR
CVE-2020-28446 is a command injection vulnerability in the ntesseract npm package that allows attackers to execute arbitrary commands on the host system. The vulnerability exists in lib/tesseract.js where user input is improperly sanitized before being passed to system commands. This affects any application using vulnerable versions of ntesseract for OCR processing.
💻 Affected Systems
- ntesseract npm package
📦 What is this software?
Ntesseract by Ntesseract Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing remote code execution, data theft, lateral movement, and complete control of affected systems.
Likely Case
Remote code execution leading to data exfiltration, cryptocurrency mining, or ransomware deployment on vulnerable servers.
If Mitigated
Limited impact with proper input validation, sandboxing, and least privilege execution preventing command execution.
🎯 Exploit Status
Exploitation requires user input to reach the vulnerable function, which is common in OCR processing workflows.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.2.9 and later
Vendor Advisory: https://github.com/taoyuan/ntesseract/commit/fcbc36f381798b4362179c0cdf9961b437c7b619
Restart Required: Yes
Instructions:
1. Update package.json to specify ntesseract version 0.2.9 or higher. 2. Run 'npm update ntesseract'. 3. Restart the application. 4. Test OCR functionality.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation to reject any non-alphanumeric characters in OCR input parameters.
Sandbox Execution
allRun the Node.js application in a container or sandbox with limited permissions to restrict command execution impact.
🧯 If You Can't Patch
- Implement strict input validation to reject shell metacharacters in all user inputs
- Run the application with minimal privileges and in a containerized environment
🔍 How to Verify
Check if Vulnerable:
Check package.json or run 'npm list ntesseract' to see if version is below 0.2.9.Check Version:
npm list ntesseract | grep ntesseractVerify Fix Applied:
After updating, verify version is 0.2.9 or higher with 'npm list ntesseract' and test OCR functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns
- Spawned processes from Node.js with unexpected arguments
- Failed OCR processing with error messages containing shell commands
Network Indicators:
- Outbound connections from OCR processing servers to unexpected destinations
- Data exfiltration patterns following OCR operations
SIEM Query:
process.name: "node" AND process.args: "*;*" OR process.args: "*|*" OR process.args: "*&*" OR process.args: "*`*"