A German security company has released an unauthorized patch for Apple's OS X Mavericks that it claimed closes the hole the Cupertino, Calif. giant left wide open in the operating system's implementation of basic Internet encryption.
Cologne, Germany-based SektionEins GmbH published the patch on Saturday, the day after Apple updated its iOS 7 and iOS 6 mobile operating systems to fix a flaw in their handling of SSL (secure socket layer) and TLS (transport layer security). Those protocols create an encrypted connection between a personal computer and a server -- such as one at Amazon.com -- so that snoopers cannot read the traffic and extract information like credit card numbers or log-in credentials.
According to many security researchers, SektionEins' (which translates to "SectionOne" in English) among them, OS X Mavericks contains the same critical vulnerability.
SektionEins' blog detailed the flaw in Mavericks and provided a link to the unofficial patch.
Unauthorized patches are rare; the last time someone offered one for the more widely-used Windows, for instance, was 2006-2007, when a group calling themselves ZERT (Zeroday Emergency Response Team), issued several home-brewed patches for bugs in Windows and Internet Explorer.
Users should be wary of unsanctioned fixes, as there's no guarantee that they work or are even clean of malicious code. Cyber criminals have used the lure of security updates to plant malware on machines for years, for example.
SektionEins was clear about the risks users took if they applied the home-grown Mavericks patch. "You should not attempt to run this on production systems," the company said on its blog. "We strongly consider this patch experimental and you should only apply it to your systems if you understand the risk."
The German firm's website has been in operation since 2007, according to Internet domain registration records.
Apple today confirmed that it is working on a Mavericks update. "We are aware of this issue and already have a software fix that will be released very soon," a spokeswoman said in an email reply to questions Monday.
But users who are leery of installing a third-party patch -- as most should be -- can take other steps to protect themselves until Apple ships a fix for OS X.
"iOS is a no-brainer, update, as in you should have updated yesterday," said Andrew Storms, director of DevOps at San Francisco's CloudPassage, in a Monday interview. "OS X is more concerning because there's no word from Apple about exactly when they're going to patch it. That's classic Apple, keeping mum."
Like other security experts, Storms urged users to refrain from using their Macs at public Wi-Fi hotspots, the most obvious and easiest places for hackers to attempt "man-in-the-middle" attacks, where the criminals interpose themselves between the client computer and server, then snatch the unencrypted bits from the ether.
He also said users can protect themselves by using an alternative to Safari, which relies on the vulnerability cryptographic code libraries. According to the quick-and-dirty test site gotofail.com both Google's Chrome and Mozilla's Firefox are secure.
But while it may be safe to access the Web using Chrome or Firefox at a public, unencrypted Wi-Fi hotspot, Storms pointed out that a slew of other applications, including those for social networking services and Apple's native OS X applications, ranging from Mail to Calendar, are not.
When Apple does issue a fix for Mavericks, it will place a notation on this page and begin offering it to users who manually launch Software Update from the Apple menu. Others will receive it automatically, as Mavericks regularly pings Apple's servers.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is firstname.lastname@example.org.