In an email sent overnight on Monday, the Linux vendor warned users to update all machines running recent versions of Ubuntu, ranging from 6.06, which was released back in mid-2006, to version 8.04, which came out earlier this year. The problem also applied to other versions of Ubuntu such as Kubuntu, Edubuntu and Xubuntu.
"It was discovered that there were multiple NULL-pointed function de-references in the Linux kernel terminal handling code," wrote Ubuntu administrators in the email. "A local attacker could exploit this to execute arbitrary code as root, or crash the system, leading to a denial of service."
The email also detailed a number of other bugs which could be exploited by an attacker who already had some level of access to a computer running Ubuntu.
A number of other Linux vendors including Novell have recently released similar patches to address the problems.