As it promised last week, Skype today began serving up an update to Mac users of its chat and Internet phone software, fixing a dangerous bug that a researcher said could be used to build a worm.
A new version of Skype marked as 184.108.40.2065 is now being offered to Mac users when they launch older editions of the program.
"We recommend that everyone upgrade to the newly released build," Skype said on a company blog today.
The update patches a vulnerability disclosed last week by Australian researcher Gordon Maddern, who had reported the issue to Skype more than a month before.
"The long and the short of it is that an attacker needs only to send a victim a message and they can gain remote control of the victim's Mac," said Maddern on his own blog. "It is extremely wormable and dangerous."
On Friday, Skype said it had already patched Maddern's vulnerability in version 220.127.116.112, which it had released on April 14. The company had not automatically offered that version to users or publicized the flaw, however, saying, "As there were no reports of this vulnerability being exploited in the wild, we did not prompt our users to install this update." Instead, users were required to update manually to receive the patch.
Skype clients for Windows and Linux do not contain the vulnerability, the company said last week.
Version 18.104.22.1685 can be downloaded and installed by clicking the "Update" button in the dialog that appears when Mac users launch the program.
Mac users of Skype will see this dialog urging them to patch the program.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed. His e-mail address is email@example.com.
Read more about security in Computerworld's Security Topic Center.