CVE-2023-51309
📋 TL;DR
This vulnerability in PHPJabbers Car Park Booking System allows attackers to send excessive emails through the Email Settings feature due to missing rate limiting. This can cause denial of service by overwhelming email servers with spam. Organizations using the vulnerable version are affected.
💻 Affected Systems
- PHPJabbers Car Park Booking System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Email servers become overwhelmed and unresponsive, disrupting legitimate email communications and potentially causing business operations impact.
Likely Case
Email server performance degradation, increased spam filtering load, and potential temporary email service disruption.
If Mitigated
Minimal impact with proper rate limiting and email server protections in place.
🎯 Exploit Status
Exploitation requires access to the Email Settings feature, which typically requires authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found in provided references
Restart Required: No
Instructions:
Check vendor website for updates. If patch available, download and apply according to vendor instructions.
🔧 Temporary Workarounds
Implement Rate Limiting
allAdd rate limiting to the Email Settings feature to restrict number of emails sent per time period.
Modify PHP code to implement request throttling or use web server rate limiting
Restrict Access
allLimit access to Email Settings feature to trusted users only.
Configure web server or application authentication to restrict access
🧯 If You Can't Patch
- Implement network-level rate limiting using WAF or reverse proxy
- Monitor email server logs for unusual email sending patterns
🔍 How to Verify
Check if Vulnerable:
Check if running PHPJabbers Car Park Booking System v3.0 and test if Email Settings allows unlimited email sending.Check Version:
Check application version in admin panel or configuration filesVerify Fix Applied:
Test if rate limiting is now enforced in Email Settings feature.📡 Detection & Monitoring
Log Indicators:
- Unusually high volume of email sending from application
- Multiple rapid requests to email settings endpoint
Network Indicators:
- High SMTP traffic from application server
- Spike in outbound email traffic
SIEM Query:
source="application_logs" AND (message="email_sent" OR endpoint="/email-settings") | stats count by src_ip | where count > threshold