CVE-2020-7727
📋 TL;DR
CVE-2020-7727 is a prototype pollution vulnerability in the gedi package that allows attackers to inject arbitrary properties into JavaScript objects, potentially leading to remote code execution or denial of service. All versions of the gedi package are affected. Applications using this package for JSON/XML processing are vulnerable.
💻 Affected Systems
- gedi
📦 What is this software?
Gedi by Gedi Project
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Denial of service, application crashes, or unauthorized data manipulation.
If Mitigated
Limited impact if input validation and sandboxing prevent exploitation.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available. Exploitation requires user-controlled input to the set() function.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: https://snyk.io/vuln/SNYK-JS-GEDI-598803
Restart Required: No
Instructions:
1. Remove gedi package from your project. 2. Use alternative JSON/XML processing libraries like lodash.set or implement custom safe setters. 3. Update package.json to remove gedi dependency.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation to prevent malicious payloads from reaching the set() function.
Object.freeze() on Prototypes
allFreeze Object.prototype and other base prototypes to prevent pollution.
Object.freeze(Object.prototype);
Object.freeze(Object);
🧯 If You Can't Patch
- Implement WAF rules to block requests containing prototype pollution patterns
- Isolate affected applications in network segments with strict egress filtering
🔍 How to Verify
Check if Vulnerable:
Check package.json for gedi dependency: grep -r 'gedi' package.jsonCheck Version:
npm list gediVerify Fix Applied:
Verify gedi is removed from package.json and node_modules directory📡 Detection & Monitoring
Log Indicators:
- Unusual application crashes
- Unexpected property assignments in logs
- Error messages referencing prototype modifications
Network Indicators:
- HTTP requests with JSON payloads containing __proto__ or constructor properties
SIEM Query:
source=web_logs AND ("__proto__" OR "constructor.prototype")