Linux, Unix 'had more vulnerabilities than Windows'

Linux/Unix-based operating systems -- a set that includes Mac OS X, as well as the various Linux distributions and flavours of Unix -- had more than twice as many vulnerabilities as Windows, according to the United States Computer Emergency Readiness Team (US-CERT), which is part of the US Department of Homeland Security.

The report -- Cyber Security Bulletin 2005 -- was published last week and found that out of 5,198 reported vulnerabilities, 812 were Windows operating system vulnerabilities, while 2,328 were Unix/Linux operating vulnerabilities. Two thousand and fifty eight were multiple operating system vulnerabilities.

However, the popularity of Windows means it is still much more likely to be attacked than Linux, according to security firm McAfee.

"In the Windows vs Unix debate, the number of vulnerabilities is less relevant than the amount that are turned into successful attacks. We see far more successful attacks against Windows, because it's the most common environment," Greg Day, security analyst at McAfee, said.

"As Linux becomes more common, we'll see more attacks against it," Day added.

McAfee recommended firms look more at the probability of attack, rather than whether an attack is possible.

CERT's report did not include figures for how quickly vulnerabilities are patched once they are discovered. According to security firm Secunia, 124 of its security advisories relate to flaws in Windows XP Professional, of which 29 are unpatched -- which gives it a lands Microsoft's operating system with a "Highly Critical" security rating.

In contrast, Red Hat 9 is affected by 99 Secunia warnings, but only one of these flaws has not been patched by Red Hat. SuSE Linux Enterprise Server 9 is covered in 91 advisories, but every one has been patched by the vendor. Both products get a 'Not Critical' rating.

Tom Espiner of ZDNet UK reported from London