CVE-2025-70347
📋 TL;DR
A vulnerability in mquickjs allows local attackers to cause denial of service by providing a specially crafted file to the get_mblock_size function. This affects systems running vulnerable versions of mquickjs where local users can submit files for processing. The issue requires local access to exploit.
💻 Affected Systems
- mquickjs
⚠️ 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 of applications using mquickjs, potentially crashing the entire process and affecting dependent services.
Likely Case
Local denial of service affecting the specific mquickjs process, requiring restart of affected applications.
If Mitigated
Minimal impact with proper access controls limiting local user privileges and file upload restrictions.
🎯 Exploit Status
Exploitation requires local access and ability to submit crafted files to the vulnerable function.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 74b7e and later (2026-01-15+)
Vendor Advisory: https://github.com/bellard/mquickjs/issues/56
Restart Required: Yes
Instructions:
1. Update mquickjs to commit 74b7e or later. 2. Rebuild any applications using mquickjs. 3. Restart affected services.
🔧 Temporary Workarounds
Restrict file upload permissions
linuxLimit which local users can submit files to mquickjs processes
chmod 750 /path/to/mquickjs/directories
setfacl -m u:trusteduser:rwx /path/to/mquickjs
Implement file validation
allAdd input validation for files before passing to mquickjs
🧯 If You Can't Patch
- Implement strict access controls to limit which local users can interact with mquickjs
- Monitor for abnormal process crashes and implement automatic restart mechanisms
🔍 How to Verify
Check if Vulnerable:
Check mquickjs version: git log --oneline | grep -i '74b7e' - if not found, vulnerableCheck Version:
git log --oneline | head -1Verify Fix Applied:
Verify commit 74b7e is present: git log --oneline | grep '74b7e'📡 Detection & Monitoring
Log Indicators:
- Process crashes of mquickjs
- Segmentation fault errors in system logs
- Abnormal termination of services using mquickjs
Network Indicators:
- No network indicators - local exploit only
SIEM Query:
process_name:"mquickjs" AND event_type:"process_crash"