Feeds

Skype squishes cross-zone scripting bug

Underlying weakness nixed

Using blade systems to cut costs and sharpen efficiencies

Skype has fixed a cross-zone scripting weakness in its voice over IP client software which spawned a couple of security bugs over recent weeks.

Problems have arisen for Windows users because Skype uses Internet Explorer web controls to render internal and external HTML pages.

Skype is running these web controls in Local Zone and, worse, accessing HTML pages in an unlocked Local Zone mode, an approach that opens the door to so-called cross-zone scripting exploits.

For example, the use of vulnerable controls made it possible to inject a malicious script into the "Add video to chat" dialogue on video-sharing sites such as Skype partner DailyMotion. Skype was initially obliged to block the feature after the vulnerability was discovered last month.

A similar vulnerability in the SkypeFind feature, which lets users recommend businesses to others running the VoIP client, also stemmed from the same underlying cross-zone scripting weakness. Skype patched the feature when the SkypeFind problem came up last week, but the underlying issue remained.

Tuesday brought the arrival of a more complete fix that addresses the underlying architectural weakness involved in both the SkypeFind and DailyMotion security flaps.

Skype said it fixed the core vulnerability by setting IE control security context to Internet Zone (instead of local zone, as previously implemented). Windows users need to update to Skype for Windows version 3.6.*.248 or later, as explained in an advisory here.

More background on cross-zone scripting vulnerabilities can be found in postings by security researcher Aviv Raff, who's kept a close watching brief on the issue over recent weeks. ®

Boost IT visibility and business value

More from The Register

next story
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
Four fake Google haxbots hit YOUR WEBSITE every day
Goog the perfect ruse to slip into SEO orfice
Putin: Crack Tor for me and I'll make you a MILLIONAIRE
Russian Interior Ministry offers big pile o' roubles for busting pro-privacy browser
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.