CVE-2024-43102
📋 TL;DR
This CVE describes a use-after-free vulnerability in FreeBSD's umtx (user mutex) subsystem where concurrent destruction of anonymous shared memory mappings can cause premature freeing of kernel objects. This allows local attackers to crash the kernel or potentially execute arbitrary code, including escaping Capsicum sandboxes. Only FreeBSD systems are affected.
💻 Affected Systems
- FreeBSD
📦 What is this software?
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to denial of service, or arbitrary code execution with kernel privileges enabling full system compromise and Capsicum sandbox escape.
Likely Case
Kernel panic causing system crash and denial of service, requiring reboot.
If Mitigated
Limited impact if proper access controls prevent local users from executing malicious code.
🎯 Exploit Status
Exploitation requires local access and knowledge of kernel internals. The advisory mentions potential for code execution but doesn't confirm weaponized exploits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FreeBSD 13.3-RELEASE-p5, 14.1-RELEASE-p1, and 14-STABLE after r327828
Vendor Advisory: https://security.freebsd.org/advisories/FreeBSD-SA-24:14.umtx.asc
Restart Required: Yes
Instructions:
1. Update FreeBSD using 'freebsd-update fetch' and 'freebsd-update install' for RELEASE versions. 2. For STABLE versions, update source and rebuild kernel. 3. Reboot system after patching.
🔧 Temporary Workarounds
No known workarounds
allThis is a kernel-level vulnerability with no configuration-based workarounds documented.
🧯 If You Can't Patch
- Restrict local user access to essential personnel only
- Implement strict monitoring of kernel panic events and suspicious local process behavior
🔍 How to Verify
Check if Vulnerable:
Check FreeBSD version with 'uname -a'. If version is before 13.3-RELEASE-p5, 14.1-RELEASE-p1, or 14-STABLE r327828, system is vulnerable.Check Version:
uname -aVerify Fix Applied:
After patching and reboot, verify version with 'uname -a' shows patched version. Check that 'freebsd-update fetch' reports no available updates.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/messages
- Unexpected system reboots
- Processes attempting unusual umtx operations
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("panic" OR "umtx" OR "UMA")