CVE-2025-47154
📋 TL;DR
This CVE describes a use-after-free vulnerability in LibJS within the Ladybird browser that allows remote attackers to execute arbitrary code via a crafted JavaScript file. The vulnerability occurs due to improper handling of argument list vector freeing. Only developers using Ladybird in its pre-alpha state are affected.
💻 Affected Systems
- Ladybird Browser
⚠️ 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 system compromise with remote code execution leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Limited impact due to Ladybird's pre-alpha status and limited user base, but developers testing the browser could have their systems compromised.
If Mitigated
No impact if Ladybird is not installed or if the patch is applied; minimal impact if used in isolated development environments.
🎯 Exploit Status
Exploit details and proof-of-concept are publicly available in blog posts and GitHub discussions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit f5a670421954fc7130c3685b713c621b29516669 and later
Vendor Advisory: https://github.com/LadybirdBrowser/ladybird/commit/f5a670421954fc7130c3685b713c621b29516669
Restart Required: Yes
Instructions:
1. Update Ladybird to latest version from GitHub repository. 2. Rebuild from source if using self-compiled version. 3. Restart the browser after update.
🔧 Temporary Workarounds
Disable JavaScript Execution
allPrevent execution of JavaScript files in Ladybird browser
Not applicable - configuration setting in browser
Use Alternative Browser
allSwitch to stable, production-ready browsers for development/testing
🧯 If You Can't Patch
- Uninstall Ladybird browser completely from affected systems
- Isolate Ladybird usage to virtual machines or containers with no network access
🔍 How to Verify
Check if Vulnerable:
Check Ladybird version/commit hash against vulnerable range (before f5a6704)Check Version:
Check git log or build information in Ladybird browserVerify Fix Applied:
Verify current commit includes f5a670421954fc7130c3685b713c621b29516669 or later📡 Detection & Monitoring
Log Indicators:
- Unexpected crashes of Ladybird browser
- Memory access violation errors in system logs
Network Indicators:
- Downloads of .js files from untrusted sources to Ladybird browser
SIEM Query:
Process execution: ladybird.exe OR ladybird AND (file extension: .js OR memory violation)