Skype patches 'wormable' Mac bug

Makes good on promise, offers update when Mac users launch Skype software

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 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, 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 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

Read more about security in Computerworld's Security Topic Center.

Join the CSO newsletter!

Error: Please check your email address.

Tags skypeMac OSsecuritysoftwareMalware and Vulnerabilitiesoperating systems

More about AppleLinuxMicrosoftPurePure HackingSkypeTopic

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Gregg Keizer

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

More videos

Blog Posts

Market Place