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.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Link | Tags |
|---|---|
| https://www.exploit-db.com/exploits/8265 | exploit |
| http://www.securityfocus.com/bid/34202 | vdb entry exploit |
| http://secunia.com/advisories/34424 | third party advisory |
| http://www.digit-labs.org/files/exploits/xnu-vfssysctl-dos.c | exploit |
| http://www.informationweek.com/news/hardware/mac/showArticle.jhtml?articleID=216401181 |