CVE-2009-1238: Apple Mac OS X

High severity, CVSS 7.2. EPSS: 0.6% chance of exploitation in the next 30 days.

Race condition in the HFS vfs sysctl interface in XNU 1228.8.20 and earlier on Apple Mac OS X 10.5.6 and earlier allows local users to cause a denial of service (kernel memory corruption) by simultaneously executing the same HFS_SET_PKG_EXTENSIONS code path in multiple threads, which is problematic because of lack of mutex locking for an unspecified global variable.

Affected products

• Apple Mac OS X: up to and including 10.5.6; version 10.0 only; version 10.0.0 only; version 10.0.1 only; version 10.0.2 only; version 10.0.3 only; …
• Apple Mac OS X Server: up to and including 10.5.6; version 10.0 only; version 10.0.0 only; version 10.0.1 only; version 10.0.2 only; version 10.0.3 only; …

Published 2009-04-02. Last modified 2026-06-16.