CVE-2023-39371
📋 TL;DR
StarTrinity Softswitch version 2023-02-16 contains an open redirect vulnerability (CWE-601) that allows attackers to redirect users to malicious websites. This affects organizations using this specific version of the VoIP softswitch software. Attackers can exploit this to conduct phishing attacks or redirect users to malware.
💻 Affected Systems
- StarTrinity Softswitch
📦 What is this software?
Softswitch by Startrinity
⚠️ Risk & Real-World Impact
Worst Case
Users redirected to sophisticated phishing sites that steal credentials or install malware, leading to full system compromise and data exfiltration.
Likely Case
Users redirected to phishing pages attempting to steal login credentials or personal information.
If Mitigated
Limited impact with proper user awareness training and browser security controls in place.
🎯 Exploit Status
Open redirect vulnerabilities typically require minimal technical skill to exploit once the vulnerable endpoint is identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.gov.il/en/Departments/faq/cve_advisories
Restart Required: No
Instructions:
1. Check vendor advisory for patch availability. 2. If patch exists, download and apply according to vendor instructions. 3. Verify the fix by testing redirect functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side validation to reject or sanitize URLs in redirect parameters
Implement URL validation in application code to only allow relative paths or approved domains
Web Application Firewall Rule
allBlock requests containing suspicious redirect parameters
Configure WAF to block requests with external URLs in redirect parameters
🧯 If You Can't Patch
- Implement network segmentation to isolate the softswitch from critical systems
- Deploy web application firewall with rules to detect and block open redirect attempts
🔍 How to Verify
Check if Vulnerable:
Test redirect functionality by attempting to redirect to external domains using crafted URLsCheck Version:
Check software version in administration interface or configuration filesVerify Fix Applied:
Verify that redirects only work for relative paths or approved domains📡 Detection & Monitoring
Log Indicators:
- HTTP requests with external URLs in redirect parameters
- Unusual redirect patterns in access logs
Network Indicators:
- HTTP 302/301 redirects to suspicious external domains
- Unusual traffic patterns following redirects
SIEM Query:
source="softswitch" AND (url="*redirect=*http://*" OR url="*redirect=*https://*")