CVE-2020-28478: Greensock GSAP Security Vulnerability

CVE-2020-28478 Overview

CVE-2020-28478 is a Denial of Service (DoS) vulnerability affecting the GreenSock Animation Platform (GSAP) package for Node.js. This vulnerability exists in versions prior to 3.6.0 and can be exploited remotely over the network without requiring authentication or user interaction.

Critical Impact

Attackers can remotely trigger a denial of service condition, causing application unavailability. The vulnerability requires no authentication and can be exploited from the network with low complexity.

Affected Products

• GreenSock Animation Platform (GSAP) versions prior to 3.6.0
• Node.js applications utilizing the vulnerable GSAP package

Discovery Timeline

• 2021-01-19 - CVE-2020-28478 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2020-28478

Vulnerability Analysis

This vulnerability affects the GSAP (GreenSock Animation Platform) JavaScript animation library, which is widely used for creating high-performance animations in web applications. The flaw resides in the core functionality of the library and can lead to a denial of service condition when exploited.

The vulnerability allows an attacker to cause resource exhaustion or application crash through maliciously crafted input. Since the attack vector is network-based and requires no privileges or user interaction, it presents a significant risk to applications that process untrusted input through GSAP functions.

Root Cause

The root cause stems from insufficient input validation in the GSAP core module. According to the GitHub GSAP Source Code, the vulnerable code path exists in gsap-core.js. Without proper bounds checking or input sanitization, specially crafted input can trigger conditions that exhaust system resources or cause the application to become unresponsive.

Attack Vector

The attack can be conducted remotely over the network. An attacker does not need any privileges or user interaction to exploit this vulnerability. The attack complexity is low, making it accessible to attackers with minimal technical expertise.

The exploitation typically involves:

1. Identifying an application endpoint that processes input through GSAP functions
2. Crafting malicious input designed to trigger resource exhaustion
3. Sending the payload to the target application
4. The application becomes unresponsive or crashes due to the DoS condition

For detailed technical information about this vulnerability, refer to the Snyk Vulnerability Advisory.

Detection Methods for CVE-2020-28478

Indicators of Compromise

• Sudden application unresponsiveness or crashes in Node.js applications using GSAP
• Abnormal memory or CPU consumption patterns in web application processes
• Increased error rates in application logs related to animation or rendering functions
• Service degradation coinciding with unusual network traffic patterns

Detection Strategies

• Monitor Node.js application health metrics for abnormal resource consumption
• Implement application-level monitoring to detect GSAP-related exceptions and errors
• Use Software Composition Analysis (SCA) tools to identify vulnerable GSAP versions in your codebase
• Scan package.json and package-lock.json files for GSAP versions below 3.6.0

Monitoring Recommendations

• Configure alerts for sudden spikes in memory or CPU usage in Node.js processes
• Implement rate limiting on endpoints that process animation-related input
• Monitor application logs for repeated crashes or restarts
• Use dependency scanning in CI/CD pipelines to detect vulnerable GSAP versions

How to Mitigate CVE-2020-28478

Immediate Actions Required

• Upgrade GSAP to version 3.6.0 or later immediately
• Audit all applications and dependencies for vulnerable GSAP versions
• Implement input validation for any user-controlled data processed by GSAP functions
• Consider implementing rate limiting on affected endpoints as a temporary measure

Patch Information

The vulnerability has been addressed in GSAP version 3.6.0. Organizations should upgrade to this version or later to remediate the vulnerability. The fix can be applied by updating the package dependency:

# Update GSAP to the latest secure version
npm update gsap

# Or install a specific patched version
npm install gsap@3.6.0

For more information, review the Snyk Vulnerability Advisory for detailed remediation guidance.

Workarounds

• Implement strict input validation before passing data to GSAP functions
• Deploy Web Application Firewall (WAF) rules to filter potentially malicious requests
• Isolate GSAP processing in separate worker threads to limit impact of DoS conditions
• Monitor and restart affected services automatically upon detection of unresponsive states

# Configuration example for package.json to enforce minimum GSAP version
# Add to package.json overrides (npm 8.3+) or resolutions (yarn)
{
  "overrides": {
    "gsap": ">=3.6.0"
  }
}