CVE-2023-4050
📋 TL;DR
This vulnerability allows an attacker to cause a stack buffer overflow by sending untrusted input without proper size validation. If exploited, it could lead to a sandbox escape in Firefox browsers, potentially executing arbitrary code. It affects Firefox versions before 116, Firefox ESR before 102.14, and Firefox ESR before 115.1.
💻 Affected Systems
- Mozilla Firefox
- Mozilla Firefox ESR
📦 What is this software?
Firefox by Mozilla
Firefox by Mozilla
Firefox by Mozilla
⚠️ Risk & Real-World Impact
Worst Case
Complete sandbox escape leading to remote code execution with user privileges, potentially compromising the entire system.
Likely Case
Browser crash or denial of service, with potential for limited code execution within browser context.
If Mitigated
Browser crash without code execution if sandbox protections hold.
🎯 Exploit Status
Exploitation requires bypassing browser sandbox protections after triggering the buffer overflow.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firefox 116, Firefox ESR 102.14, Firefox ESR 115.1
Vendor Advisory: https://bugzilla.mozilla.org/show_bug.cgi?id=1843038
Restart Required: Yes
Instructions:
1. Open Firefox. 2. Click menu → Help → About Firefox. 3. Allow automatic update download and installation. 4. Restart Firefox when prompted.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript to prevent exploitation via web content.
about:config → javascript.enabled → false
Use alternative browser
allSwitch to updated or unaffected browser until Firefox is patched.
🧯 If You Can't Patch
- Restrict browser use to trusted websites only
- Implement network filtering to block malicious content delivery
🔍 How to Verify
Check if Vulnerable:
Check Firefox version in About Firefox dialog or via 'firefox --version' command.Check Version:
firefox --versionVerify Fix Applied:
Confirm version is Firefox ≥116, Firefox ESR ≥102.14, or Firefox ESR ≥115.1.📡 Detection & Monitoring
Log Indicators:
- Firefox crash reports with stack overflow indicators
- Unexpected browser termination events
Network Indicators:
- Unusual web requests to known malicious domains delivering exploit code
SIEM Query:
source="firefox.log" AND ("crash" OR "segmentation fault" OR "buffer overflow")🔗 References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1843038
- https://lists.debian.org/debian-lts-announce/2023/08/msg00008.html
- https://lists.debian.org/debian-lts-announce/2023/08/msg00010.html
- https://www.debian.org/security/2023/dsa-5464
- https://www.debian.org/security/2023/dsa-5469
- https://www.mozilla.org/security/advisories/mfsa2023-29/
- https://www.mozilla.org/security/advisories/mfsa2023-30/
- https://www.mozilla.org/security/advisories/mfsa2023-31/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1843038
- https://lists.debian.org/debian-lts-announce/2023/08/msg00008.html
- https://lists.debian.org/debian-lts-announce/2023/08/msg00010.html
- https://www.debian.org/security/2023/dsa-5464
- https://www.debian.org/security/2023/dsa-5469
- https://www.mozilla.org/security/advisories/mfsa2023-29/
- https://www.mozilla.org/security/advisories/mfsa2023-30/
- https://www.mozilla.org/security/advisories/mfsa2023-31/
