Menu
Yahoo Messenger zero-day exploits on the loose

Yahoo Messenger zero-day exploits on the loose

'Extremely critical' bugs let attackers snatch control of Windows PCs via IM

Shortly after eEye Digital Security notified Yahoo Wednesday that the portal's Messenger IM client was vulnerable to attack, a researcher fingered two ActiveX controls as flawed and posted exploit code that can be used to hijack Windows machines.

Although eEye's advisory was vague about details -- it said Messenger's Webcam ActiveX control was at fault -- the researcher laid all bare on the full-disclosure list.

The researcher, who went by the name "Danny," cited "45 minutes of fuzzing!" in a post Wednesday about the flaw. In a follow-up today, Danny published a second exploit. "This affects the viewer ywcvwr.dll with yahoo messenger," he said.

Aliso, eEye called the Yahoo Messenger bugs serious. "ActiveX remote code execution vulnerabilities have very high impacts since the source of the malicious payload can be any site," the security vendor said. "An even more critical problem is generated when clients are administrators on their local hosts, which would run the malicious payload with administrator credentials."

Most Windows XP users run in administrator mode.

Danish vulnerability tracker Secunia rated the Messenger bugs as "extremely critical" -- its highest-possible threat ranking.

Until Yahoo provides a patch, eEye said the only work-around defense is to set the kill-bit for the two Yahoo ActiveX controls. However, because that involves manually editing the Windows registry, it's not a tactic most users will feel comfortable doing. Microsoft, which in the past has recommended kill-bitting to temporarily protect users against vulnerabilities in Internet Explorer and its other software, has offered a set of technical instructions on setting kill bits.

Yahoo has not yet posted a fix for the flaws to its security update page. The last Messenger bug, also because of a vulnerable ActiveX control, was fixed in April.


Follow Us

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Featured

Slideshows

Meet the leading female front runners of the Kiwi channel

Meet the leading female front runners of the Kiwi channel

Reseller News honoured the leading female front runners of the New Zealand channel at the 2018 Women in ICT Awards (WIICTA) in Auckland. The awards honoured standout individuals across seven categories, spanning Entrepreneur; Innovation; Rising Star; Shining Star; Community; Technical and Achievement.

Meet the leading female front runners of the Kiwi channel
Meet the top performing customer-centric Microsoft channel partners

Meet the top performing customer-centric Microsoft channel partners

Microsoft honoured leading partners across the channel following a year of customer innovation and market growth in New Zealand. The 2018 Microsoft Partner Awards recognised excellence within the context of the end-user, spanning a host of emerging and established providers.

Meet the top performing customer-centric Microsoft channel partners
Reseller News launches new-look Awards at 2018 Judges’ Lunch

Reseller News launches new-look Awards at 2018 Judges’ Lunch

Introducing the Reseller News Innovation Awards, launched to the channel at the 2018 Judges’ Lunch in Auckland. With more than 70 judges now part of the voting panel, the new-look awards will reflect the changing dynamics of the channel, recognising excellence across customer value and innovation - spanning start-ups, partners, distributors and vendors.

Reseller News launches new-look Awards at 2018 Judges’ Lunch
Show Comments