CVE-2018-3739
📋 TL;DR
CVE-2018-3739 is a vulnerability in https-proxy-agent where improper sanitization of the 'auth' parameter allows attackers to cause denial of service and leak uninitialized memory. This affects applications using vulnerable versions of https-proxy-agent to handle HTTP proxy authentication, particularly when user-controlled input is passed to the auth parameter.
💻 Affected Systems
- https-proxy-agent
📦 What is this software?
Https Proxy Agent by Https Proxy Agent Project
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption through DoS and potential memory disclosure leading to further exploitation
Likely Case
Service degradation or crash when malicious auth input is processed
If Mitigated
Minimal impact with proper input validation and updated dependencies
🎯 Exploit Status
Exploitation requires ability to submit input to auth parameter, which may be possible through various application interfaces
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.1.1 and later
Vendor Advisory: https://hackerone.com/reports/319532
Restart Required: Yes
Instructions:
1. Update https-proxy-agent to version 2.1.1 or later using npm update https-proxy-agent
2. Restart affected applications
3. Verify no dependencies are pulling in vulnerable versions
🔧 Temporary Workarounds
Input Validation
allImplement strict input validation for auth parameters before passing to https-proxy-agent
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems
- Deploy WAF rules to block suspicious auth parameter patterns
🔍 How to Verify
Check if Vulnerable:
Check package.json or run npm list https-proxy-agent to see if version <2.1.1 is installedCheck Version:
npm list https-proxy-agent | grep https-proxy-agentVerify Fix Applied:
Confirm https-proxy-agent version is 2.1.1 or higher via npm list https-proxy-agent📡 Detection & Monitoring
Log Indicators:
- Application crashes or high memory usage when processing proxy auth
- Unusual auth parameter values in logs
Network Indicators:
- Unusual patterns in proxy authentication requests
SIEM Query:
source="application_logs" AND ("https-proxy-agent" OR "proxy auth") AND ("crash" OR "memory" OR "uninitialized")