Integer overflow in the ffs_mountfs function in Mac OS X 10.4.8 and FreeBSD 6.1 allows local users to cause a denial of service (panic) and possibly gain privileges via a crafted DMG image that causes "allocation of a negative size buffer" leading to a heap-based buffer overflow, a related issue to CVE-2006-5679.  NOTE: a third party states that this issue does not cross privilege boundaries in FreeBSD because only root may mount a filesystem.