CVE-2025-13012
📋 TL;DR
A race condition vulnerability in the Graphics component of Mozilla products could allow an attacker to execute arbitrary code or cause a denial of service. This affects Firefox, Firefox ESR, and Thunderbird users running outdated versions. Attackers could exploit this by tricking users into visiting malicious websites.
💻 Affected Systems
- Firefox
- Firefox ESR
- Thunderbird
📦 What is this software?
Firefox by Mozilla
Firefox by Mozilla
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/application crash (denial of service) or limited memory corruption leading to information disclosure.
If Mitigated
No impact if patched versions are used or if exploit attempts are blocked by security controls.
🎯 Exploit Status
Race conditions require precise timing, making exploitation challenging but possible. No public exploits confirmed yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firefox 145+, Firefox ESR 140.5+, Firefox ESR 115.30+, Thunderbird 145+, Thunderbird 140.5+
Vendor Advisory: https://www.mozilla.org/security/advisories/
Restart Required: Yes
Instructions:
1. Open Firefox/Thunderbird. 2. Click menu → Help → About Firefox/Thunderbird. 3. Allow automatic update download and installation. 4. Restart when prompted.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily reduces attack surface by disabling JavaScript execution.
about:config → javascript.enabled = false
Use Content Security Policy
allImplement CSP headers to restrict script execution from untrusted sources.
Content-Security-Policy: script-src 'self'
🧯 If You Can't Patch
- Restrict browser usage to trusted websites only
- Deploy application whitelisting to block vulnerable versions
🔍 How to Verify
Check if Vulnerable:
Check browser version in About dialog or via command line.Check Version:
firefox --version | thunderbird --versionVerify Fix Applied:
Confirm version is at or above patched versions listed in fix_official.📡 Detection & Monitoring
Log Indicators:
- Browser crash reports
- Unexpected process termination logs
- Memory access violation events
Network Indicators:
- Unusual outbound connections from browser processes
- Traffic to known exploit hosting domains
SIEM Query:
source="browser_crash_logs" AND (event_id="1000" OR event_id="1001")🔗 References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1991458
- https://www.mozilla.org/security/advisories/mfsa2025-87/
- https://www.mozilla.org/security/advisories/mfsa2025-88/
- https://www.mozilla.org/security/advisories/mfsa2025-89/
- https://www.mozilla.org/security/advisories/mfsa2025-90/
- https://www.mozilla.org/security/advisories/mfsa2025-91/
