CVE-2020-28478
📋 TL;DR
CVE-2020-28478 is a prototype pollution vulnerability in GSAP (GreenSock Animation Platform) that allows attackers to modify object prototypes, potentially leading to denial of service, remote code execution, or property injection. This affects any web application using GSAP for animations before version 3.6.0. Developers and organizations using vulnerable GSAP versions in their web applications are affected.
💻 Affected Systems
- GSAP (GreenSock Animation Platform)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution through prototype pollution leading to complete system compromise, data theft, or malware deployment.
Likely Case
Denial of service through application crashes or property injection that modifies application behavior.
If Mitigated
Limited impact if input validation and sanitization are implemented, though prototype pollution risks remain.
🎯 Exploit Status
Exploitation requires attacker-controlled input to reach vulnerable GSAP functions. Public proof-of-concept demonstrates prototype pollution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.6.0 and later
Vendor Advisory: https://greensock.com/gsap/
Restart Required: No
Instructions:
1. Update GSAP to version 3.6.0 or later. 2. For npm: run 'npm update gsap'. 3. For direct download: replace gsap.js with patched version. 4. Test animations after update.
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation for any data passed to GSAP functions to prevent prototype pollution.
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) to restrict script execution
- Use web application firewall (WAF) rules to block malicious payloads targeting prototype pollution
🔍 How to Verify
Check if Vulnerable:
Check package.json or GSAP version in your project. If using npm: 'npm list gsap'. If version is below 3.6.0, you are vulnerable.Check Version:
npm list gsap | grep gsapVerify Fix Applied:
After updating, verify GSAP version is 3.6.0 or higher. Test animation functionality to ensure no regression.📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript errors related to object properties
- Application crashes when processing animation data
Network Indicators:
- Malicious payloads in POST/GET requests containing prototype pollution patterns
SIEM Query:
search for 'gsap' AND ('prototype' OR '__proto__') in web server logs