When the SANS Institute, a computer-security training organization, released its Top-20 vulnerabilities last week, the rankings continued an annual ritual aimed at highlighting the worst flaws for network administrators. This year, the list had something different, however: the group flagged the collective vulnerabilities in Apple's Mac OS X operating system as a major threat.
It's the first time that the SANS Institute called out an entire operating system for its vulnerabilities. While the move has raised questions about the value of such a general warning, highlighting recent vulnerabilities in Mac OS X was intended as a wake up call, said Rohit Dhamankar, security architect for TippingPoint, a subsidiary of networking firm 3Com, and the editor for the SANS Top-20 vulnerability list.
"We are not pointing at the entire Mac OS X and saying you have to worry about the entire operating system," he said. "It is just that the Mac OS X is not entirely free of troubles."
The naming of Apple's Mac OS X to the list is the latest warning from security experts to users that Apple's operating system is not immune to threats. In its last two bi-annual reports, security firm Symantec has warned Apple users that the perceived security strengths of Mac OS X will not withstand determined attackers, especially with mounting vulnerabilities and at least one known rootkit tailored to the system. Symantec is the owner of SecurityFocus.
Such warnings, however, have to contend with the Mac OS X's impressive lack of major security incidents. While users of Microsoft Windows have to worry about the latest viruses, Trojan horse programs, spyware and phishing attacks, users of Apple's systems have significantly fewer threats about which to be concerned.
Still, if would-be attackers begin to focus on the operating system, then it's likely that major security incidents will not be far behind, said Nicholas Raba, CEO of Mac OS X security information and software site SecureMac.com.
"Mac OS X is currently more secure than Linux or Windows only for the fact that the shares of users is smaller thus the (number of) researchers discovering the flaws is smaller," Raba said.
Others point out that the vulnerability landscape is already shifting. The number of vulnerabilities patched by Apple in the Mac OS X rivals the number fixed by Microsoft in its operating systems, according to data from the Open Source Vulnerability Database. So far in 2005, Microsoft has released patches for 89 vulnerabilities, while Apple has released patches for 81 vulnerabilities, according to Brian Martin, content editor for the OSVDB. Counting flaws offers little more than a rough approximation of the threat to a particular operating system, Martin said, but it does show that Apple has gained the attention of the security community.
"A lot of the people who do vulnerability research started with Unix, and a lot of hackers have moved to Apple Mac OS X because it is cool and they can do anything they could do on Unix," he said.
Apple adopted its variant of the Unix operating system, the Berkeley Software Distribution or BSD, as the basis for its revamped Mac OS, which it first released in March 2001. Since then the number of flaws discovered that affect the operating system has steadily increased, to 46 in 2004 from 5 in 2001, according to the OSVDB.
However, Mac OS X does not have the same security problems that Windows does, Martin said. In many ways, Apple's operating system gains the advantages of Unix, but because Unix has not historically been a desktop operating system, many of the mistakes made by Microsoft - such as Active X controls' poor security model and unsecured services - are not present, he said. Instead, Apple users primarily need to worry about malicious Web sites that attack through the Safari browser and media files that exploit vulnerabilities in the operating system's applications. The SANS Top-20, for example, called out five different parts of the Windows operating system, including Internet Explorer, the broad Windows services category, and Windows configuration weaknesses.
Poor configuration of Mac OS X computers is also a worry, according to some network administrators.
"The problem is that there are enough OS X boxes on networks that are not patched, firewalled, and configured that they pose a clear and present danger to the networks they reside on," said one university information-technology specialist posting to the Full Disclosure security mailing list.
Security researchers also worry about Apple's hesitation to speak publicly about its operating system's security. Apple has infrequently commented on the topic of its operating system security or the company's security policies. Apple also declined to comment for this article.
Yet, including the entire operating system as a to-do item on a list of top-20 vulnerabilities is not entirely fair, OSVDB's Martin said.
"In 2005, they have about the same number of vulnerabilities in the operating system as Windows, but Microsoft has a much greater market share," Martin said. "The Mac OS doesn't deserve a spot any more than any other operating system."
SANS's Dhamankar stressed that the intent was not to call the Mac OS X operating system a threat, but to give Mac users a wake up call. If they have not been paying attention to security, then they should start today, he said.
"There are some people that feel that, if they are running Mac OS X, then all is well," Dhamankar said. "That is no longer true."
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