CVE-2023-26102
📋 TL;DR
CVE-2023-26102 is a prototype pollution vulnerability in the rangy JavaScript library that allows attackers to modify object prototypes through the extend() function. This can lead to denial of service, remote code execution, or privilege escalation in web applications using vulnerable versions. All users of the rangy package are affected.
💻 Affected Systems
- rangy
📦 What is this software?
Rangy by Rangy Project
⚠️ 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 limited data manipulation
If Mitigated
Minimal impact with proper input validation and security controls
🎯 Exploit Status
Proof of concept available in GitHub issues, exploitation requires user interaction with malicious content
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None
Vendor Advisory: https://github.com/timdown/rangy/issues/478
Restart Required: No
Instructions:
No official patch available. Remove or replace rangy library with alternative solution.
🔧 Temporary Workarounds
Remove rangy dependency
allCompletely remove rangy from your project and replace with alternative text range libraries
npm uninstall rangy
Input validation wrapper
allWrap rangy.extend() calls with input validation to prevent prototype pollution
// JavaScript wrapper example:
function safeExtend(target, source) {
if (source && source.__proto__ === Object.prototype) {
return Object.assign(target, source);
}
return rangy.extend(target, source);
}
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) to restrict script execution
- Use web application firewall (WAF) rules to detect and block prototype pollution attempts
🔍 How to Verify
Check if Vulnerable:
Check package.json for rangy dependency and verify versionCheck Version:
npm list rangyVerify Fix Applied:
Confirm rangy is removed from dependencies and not loaded in application📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript errors, prototype modification attempts, unexpected object property changes
Network Indicators:
- Malicious JavaScript payloads containing Object.prototype modifications
SIEM Query:
source="web_logs" AND ("rangy" OR "extend()" OR "prototype") AND status=500