CVE-2020-28464
📋 TL;DR
CVE-2020-28464 is a critical code injection vulnerability in the djv JSON schema validation library. An attacker who can control the schema file can execute arbitrary JavaScript code on the victim's machine, leading to remote code execution. This affects any application using vulnerable versions of the djv package.
💻 Affected Systems
- djv (JSON schema validation library)
📦 What is this software?
Djv by Djv Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the victim machine, data theft, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to application compromise, data exfiltration, and potential privilege escalation depending on application context.
If Mitigated
Limited impact if schema validation occurs in isolated environments with strict input validation and no external schema control.
🎯 Exploit Status
Exploitation requires control over schema input. Public proof-of-concept exists in GitHub pull requests and security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.1.4
Vendor Advisory: https://github.com/korzio/djv/security/advisories
Restart Required: Yes
Instructions:
1. Update djv package to version 2.1.4 or later using npm: npm update djv@2.1.4
2. Restart all applications using the djv library
3. Verify no breaking changes in your application's schema validation
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict validation and sanitization of all schema inputs before passing to djv
Schema whitelisting
allOnly allow pre-approved, known-good schemas and reject any user-provided schemas
🧯 If You Can't Patch
- Isolate the vulnerable application in a restricted network segment with no internet access
- Implement strict input validation and reject any schema containing JavaScript code or suspicious patterns
🔍 How to Verify
Check if Vulnerable:
Check package.json or run: npm list djv | grep djvCheck Version:
npm list djv | grep djvVerify Fix Applied:
Verify installed version is 2.1.4 or higher: npm list djv | grep djv@2.1.4📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript execution in schema validation context
- Schema files containing eval() or Function() calls
- Unexpected process spawning from validation routines
Network Indicators:
- Outbound connections from validation processes
- Data exfiltration patterns following schema validation
SIEM Query:
process.name:node AND cmdline:*djv* AND (cmdline:*eval* OR cmdline:*Function*)🔗 References
- https://github.com/korzio/djv/blob/master/lib/utils/properties.js%23L55
- https://github.com/korzio/djv/pull/98/files
- https://snyk.io/vuln/SNYK-JS-DJV-1014545
- https://github.com/korzio/djv/blob/master/lib/utils/properties.js%23L55
- https://github.com/korzio/djv/pull/98/files
- https://snyk.io/vuln/SNYK-JS-DJV-1014545
