Apple has released its latest security update which addresses flaws in Safari, iChat, Mail and Address Book that may lead to "unexpected application termination or arbitrary code execution". The updates are available for Mac OS X v10.4.11 and Mac OS X v10.5.1.

Security Update 2007-009 can be downloaded and installed via Apple's Software Update, or from Apple Downloads.

More reported vulnerabilities

Apple Mac computers are traditionally regarded as more stable and less prone to security problems than PCs running Microsoft Windows. But this year, Apple Mac operating systems had more critical vulnerabilities reported than Microsoft's operating systems, according to research.

Figures from security firm Secunia show that 234 highly critical vulnerabilities were reported for Mac OS X in 2007, while Windows Vista and Windows XP combined had only 23, business tech site ZDnet.com found.

This means Apple had over five times the number of security flaws per month than Windows XP and Vista during the last 12 months.

The 2007-009 security update includes fixes for Address Book, CFNetwork, ColorSync, Core Foundation, CUPS, Desktop Services, Flash Player Plug-in, GNU Tar, iChat, IO Storage Family, Launch Services, Mail, perl, python, Quick Look, ruby, Safari, Safari RSS, Samba, Shockwave Plug-in, SMB, Software Update, Spin Tracer, Spotlight, tcpdump and XQuery.