CVE-2023-53873
📋 TL;DR
SyncBreeze 15.2.24 contains a denial of service vulnerability where attackers can crash the service by sending oversized password parameters with repeated 'password=' values to the login endpoint. This affects all users running the vulnerable version of SyncBreeze file synchronization software.
💻 Affected Systems
- SyncBreeze
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption making SyncBreeze unavailable, potentially affecting file synchronization operations and business continuity.
Likely Case
Service crashes requiring manual restart, causing temporary disruption to file synchronization tasks.
If Mitigated
Minimal impact with proper network controls and monitoring in place to detect and block attack attempts.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (ID: 51725). Attack requires sending specially crafted HTTP requests to the login endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified
Vendor Advisory: https://www.syncbreeze.com/
Restart Required: No
Instructions:
Check SyncBreeze website for updated version. Upgrade to latest version if available. If no patch, implement workarounds.
🔧 Temporary Workarounds
Network Access Control
allRestrict access to SyncBreeze login endpoint using firewall rules or network segmentation.
Web Application Firewall
allConfigure WAF to block requests with oversized password parameters or repeated 'password=' values.
🧯 If You Can't Patch
- Implement network segmentation to isolate SyncBreeze from untrusted networks
- Monitor for repeated login attempts with large payloads and implement rate limiting
🔍 How to Verify
Check if Vulnerable:
Check SyncBreeze version in application interface or installation directory. If version is 15.2.24, system is vulnerable.Check Version:
Check SyncBreeze About dialog or installation propertiesVerify Fix Applied:
Verify version is no longer 15.2.24. Test login endpoint with normal authentication to ensure service remains responsive.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts with large payload sizes
- Service crash/restart events in application logs
- Unusual HTTP POST requests to login endpoint
Network Indicators:
- HTTP POST requests to /login with oversized password parameters
- Repeated 'password=' strings in request payloads
- Unusual traffic patterns to SyncBreeze port
SIEM Query:
source="syncbreeze.log" AND (event="crash" OR event="restart") OR http.method="POST" AND http.uri="/login" AND http.content_length>1000