Apple Releases Large Security Patch For OS X

Apple has released its first security patch of the year and it is a big one, designed to tackle a slew of security issues in its OS X operating system.

Most of the fixes aim to prevent potential drive-by-attacks and to fix issues in third-party products.

Hefty Download

The OS X Security Updates cover Snow Leopard (OS X 10.6) and Lion (OS X 10.7), according to the support article released by Apple 1 February.

Unlike major vendors such as Microsoft, Oracle and Adobe, Apple does not release security updates on a regular schedule. The last security update was released in June 2011, just before the company launched Lion.

The Security Update 2012-001 includes 39 fixes addressing 52 different common vulnerabilities and exposures. Apple also fixed another issue related to Secure Sockets Layer certificates that didn’t have a CVE assigned. For Snow Leopard users running the latest release, the update contains 200MB of code. But Lion users would be downloading anywhere from 700MB to 1.4GB, depending on the exact version currently installed. With this update, Lion users will be at version 10.7.3.

“This sounds like the sort of update you would ignore at your peril,” Paul Ducklin, head of technology in the Asia Pacific group at Sophos, wrote on the Naked Security blog.

Apple classified 19 of the fixes as allowing “arbitrary code execution.” Ducklin said those issues could have been exploited as part of a drive-by attack. Simply using the malicious file could have triggered the attack, such as previewing a font, listening to an audio file, watching a video, viewing an image or reading a PDF document, according to Ducklin. A wide range of file types were affected.

Data files aren’t supposed to contain harmless executable code, so users “reasonably” treat images, podcasts and videos as implicitly safe for both Macs and PCs, Ducklin said. This is one of the reasons why cyber-crooks are willing to pay for these exploits as it allows them to sneak malicious code onto victim computers using innocent-looking files, he said.

Since Apple tightly integrates third-party products into its operating system, it is responsible for patching all those products in addition to closing security flaws in its own tools. This causes it to be slightly behind the curve for some of those issues.

Apache Issues

“Multiple vulnerabilities” in Apache were fixed and both desktop and server versions of Snow Leopard and Lion are now running Apache version 2.2.21. The most serious issue, CVE 2011 3348, may cause a denial of service, according to the advisory. A remote attacker could send malformed HTTP requests and cause the server to lock up, resulting in a temporary denial of service condition.

The issue was publicised and patched by Apache back in September. Oracle patched it in its affected products in November. Apple took a little over four months.

Apple also fixed the SSL vulnerability in Apache that could have been exploited by the “BEAST” attack tool. The widespread issue revolved around how data was encrypted using CBC mode. But the flaw could also be used for man-in-the-middle attacks where the data could be decrypted. Apache, Microsoft and Oracle have already patched the flaw in their products.

Apple fixed a “downgrade issue” in which Address Book attempted to establish an unencrypted connection if it was unable to create an encrypted one. An attacker in a “privileged network position” would be able to intercept CardDAV data being sent by Address Book. The issue affected only Lion users and has been fixed to require user approval to create an unencrypted connection.

Apple also revoked the certificates issued by DigiCert Malaysia. Last fall, there were reports that DigiCert Malaysia had issued certificates with weak keys that it was unable to revoke. An attacker would have been able to intercept sensitive information intended for a site with a certificate signed by DigiCert Malaysia.