CVE-2024-6739
📋 TL;DR
This vulnerability in Openfind's MailGates and MailAudit products allows remote attackers to potentially steal session cookies via cross-site scripting (XSS) attacks because the session cookie lacks the HttpOnly flag. This affects organizations using these email security products. Attackers could hijack user sessions and gain unauthorized access to email systems.
💻 Affected Systems
- Openfind MailGates
- Openfind MailAudit
📦 What is this software?
Mailaudit by Openfind
Mailgates by Openfind
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal session cookies via XSS, hijack administrative sessions, gain full control over email security systems, access sensitive email data, and potentially pivot to internal networks.
Likely Case
Attackers steal user session cookies via XSS payloads, impersonate legitimate users to access email accounts, read sensitive communications, and potentially send malicious emails from compromised accounts.
If Mitigated
With proper XSS protections and network segmentation, impact is limited to potential session hijacking of individual users rather than system-wide compromise.
🎯 Exploit Status
Requires XSS vulnerability to be present or injected to steal cookies. HttpOnly flag absence makes cookie theft easier if XSS exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions
Vendor Advisory: https://www.openfind.com.tw/taiwan/download/Openfind_OF-ISAC-24-007.pdf
Restart Required: Yes
Instructions:
1. Download and apply the security patch from Openfind. 2. Restart the MailGates/MailAudit services. 3. Verify the HttpOnly flag is now set on session cookies.
🔧 Temporary Workarounds
Enable HttpOnly flag via configuration
allManually configure session cookies to include HttpOnly flag if supported by product configuration
Check product documentation for session cookie configuration options
Implement WAF rules
allDeploy web application firewall rules to detect and block XSS attempts
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to prevent XSS execution
- Deploy network segmentation to isolate email security systems from user networks
🔍 How to Verify
Check if Vulnerable:
Inspect session cookies in browser developer tools; check if 'HttpOnly' attribute is missing from session cookiesCheck Version:
Check product administration interface or consult vendor documentation for version check procedureVerify Fix Applied:
Verify session cookies now include 'HttpOnly' flag in Set-Cookie headers📡 Detection & Monitoring
Log Indicators:
- Unusual XSS payloads in web logs
- Multiple failed login attempts from new sessions
- Session cookies appearing in unexpected logs
Network Indicators:
- HTTP requests containing script tags or JavaScript payloads to email system endpoints
- Unusual cookie theft patterns
SIEM Query:
source="web_logs" AND (uri="*<script>*" OR uri="*javascript:*") AND dest_ip="[MAILGATES_IP]"🔗 References
- https://www.openfind.com.tw/taiwan/download/Openfind_OF-ISAC-24-007.pdf
- https://www.twcert.org.tw/en/cp-139-7928-04e8a-2.html
- https://www.twcert.org.tw/tw/cp-132-7927-03837-1.html
- https://www.openfind.com.tw/taiwan/download/Openfind_OF-ISAC-24-007.pdf
- https://www.twcert.org.tw/en/cp-139-7928-04e8a-2.html
- https://www.twcert.org.tw/tw/cp-132-7927-03837-1.html
