In rather a surprise announcement (at least on my-behalf as I have heard of them) the UK government organization responsible for gathering information on IT security incidents has issued two security advisories regarding recently identified vulnerabilities in Mac OS X.
This security vulnerability is described as a "pre-authentication, remotely exploitable stack buffer overflow that allows an attacker to obtain administrative privileges".
The other advisory describes a Mac OS X file server authentication vulnerability â also "high" risk. It is described as a buffer overflow vulnerability in the way the AppleFileServer handles certain authentication requests. UNIRAS suggests that "a remote attacker could overflow a buffer, gain root privileges, and execute arbitrary commands on the system."
The warning was issued by UNIRAS, view the alert here
They appear to old warnings and upgrading to the latest release of OS X will keep you safe