CVE-2025-3608
📋 TL;DR
A race condition in Firefox's nsHttpTransaction component could allow memory corruption, potentially leading to arbitrary code execution. This affects Firefox versions before 137.0.2. Attackers could exploit this to compromise user systems through malicious web content.
💻 Affected Systems
- Mozilla Firefox
📦 What is this software?
Firefox by Mozilla
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise, data theft, or ransomware deployment
Likely Case
Browser crash or denial of service, with potential for limited code execution in some scenarios
If Mitigated
Browser crash with no data loss if sandboxing and other security controls function properly
🎯 Exploit Status
Race conditions are timing-dependent and may be difficult to reliably exploit. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 137.0.2
Vendor Advisory: https://www.mozilla.org/security/advisories/mfsa2025-25/
Restart Required: Yes
Instructions:
1. Open Firefox. 2. Click menu → Help → About Firefox. 3. Firefox will automatically check for updates and install version 137.0.2. 4. Restart Firefox when prompted.
🔧 Temporary Workarounds
Disable JavaScript
allPrevents exploitation by disabling JavaScript execution, which is required for most web-based attacks
about:config → javascript.enabled → false
Use Enhanced Tracking Protection Strict Mode
allBlocks more trackers and potentially malicious scripts
Settings → Privacy & Security → Enhanced Tracking Protection → Strict
🧯 If You Can't Patch
- Restrict browser usage to trusted websites only
- Implement application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Firefox version: about:support → Application Basics → VersionCheck Version:
firefox --version (Linux/macOS) or check about:support (all platforms)Verify Fix Applied:
Verify version is 137.0.2 or higher in about:support📡 Detection & Monitoring
Log Indicators:
- Firefox crash reports with nsHttpTransaction in stack trace
- Unexpected browser termination events
Network Indicators:
- Multiple rapid HTTP requests to same resource from single client
- Unusual timing patterns in HTTP traffic
SIEM Query:
source="firefox.logs" AND ("nsHttpTransaction" OR "race condition" OR "memory corruption")