CVE-2025-63914
📋 TL;DR
CVE-2025-63914 is a resource exhaustion vulnerability in Cinnamon kotaemon 0.11.0 where the ZIP file extraction function lacks proper validation. Attackers with file upload permissions can upload ZIP bombs that consume excessive CPU/memory during decompression and potentially fill disk space, leading to denial of service. This affects all systems running the vulnerable version of kotaemon.
💻 Affected Systems
- Cinnamon kotaemon
📦 What is this software?
Kotaemon by Cinnamon
⚠️ Risk & Real-World Impact
Worst Case
Complete system unavailability due to disk space exhaustion and resource starvation, requiring manual intervention to restore service.
Likely Case
Temporary service degradation or unavailability during decompression attempts, with potential disk space consumption if no subsequent uploads occur.
If Mitigated
Minimal impact with proper monitoring and disk space management, though resource spikes may still occur during decompression.
🎯 Exploit Status
Exploitation requires file upload permissions. Public proof-of-concept exists in GitHub repository references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Monitor the GitHub repository for updates and apply when released.
🔧 Temporary Workarounds
Implement ZIP file size and content validation
allAdd server-side validation to check ZIP file size, compression ratio, and limit number of extracted files before processing.
# Modify _may_extract_zip function in \libs\ktem\ktem\index\file\ui.py to add validation logic
Restrict file upload permissions
allLimit file upload capabilities to trusted users only and implement rate limiting on upload endpoints.
# Configure application permissions to restrict upload access
🧯 If You Can't Patch
- Implement monitoring for abnormal disk usage and CPU spikes during file processing
- Configure disk quotas and automatic cleanup of temporary extraction directories
🔍 How to Verify
Check if Vulnerable:
Check if running kotaemon version 0.11.0 and review if _may_extract_zip function in ui.py lacks proper ZIP validation.Check Version:
python -c "import ktem; print(ktem.__version__)" or check package metadataVerify Fix Applied:
Verify that ZIP file validation has been implemented in the extraction function and test with malicious ZIP files.📡 Detection & Monitoring
Log Indicators:
- Large ZIP file uploads
- Extended processing times for file extraction
- Disk space alerts
- High CPU usage during file processing
Network Indicators:
- Large file uploads to upload endpoints
- Repeated upload attempts
SIEM Query:
source="application_logs" AND (message="*ZIP*" OR message="*extract*") AND (size>1000000 OR duration>30s)