Feeds

Scramble to fix Skype security bug

Hanging on the telephone

The Power of One eBook: Top reasons to choose HP BladeSystem

Security researchers have identified two groups of potentially serious security vulnerabilities involving Skype, the popular VoIP client software. Both create a means for hackers to run hostile code on systems running vulnerable versions of Skype. Skype has issued patches for the "critical" security bugs.

In the first case, a security bug in the Skype for Windows means the software can be crashed and forced to execute arbitrary code through a buffer overflow when presented with malformed URLs in the Skype-specific URI format callto:// and skype://. Skype can also be made to execute arbitrary code via the importation of a maliciously formated VCARD (an electronic business card format).

A second security vulnerability is not restricted to Windows PCs and hits Skype across all supported platforms. Here a heap-based buffer overflow security is the culprit but the upshot is the same as the Windows specific bug - hackers might be able to take over vulnerable systems, at least in theory. At the time of writing, neither of the security bugs is subject to either publicly available exploits or malicious code. Nonetheless users are urged to upgrade to Skype for Windows release 1.4.*.84, Skype for Mac OS X 1.3.*.17 or Skype for Linux 1.2.*.18 or later to guard against attack. No patch for Skype for Pocket PC has been released.

The vulnerabilities were discovered by Pentest and EADS Corporate Research Center. A bulletin from Secunia provides links to relevant advisories and patches. Advisories from Skype can be found here and here.

The scope - and cross-platform reach - of the vulnerabilities has security researchers worried. "Skype's ubiquity and the closed nature of their protocol means that all clients are based on the same code – Windows, Linux, business and home users all share the same, equally vulnerable client, a fecund breeding ground for worms and other malicious code," said Tom Newton, product manager for firewall vendor SmoothWall. "Skype's ease of use is partially facilitated by the port-agile firewall-dodging protocol used – this poses further danger to unsuspecting administrators who may not realise the scope of VoIP activity on their network."

In a statement, Skype said it reacted swiftly to reports of security vulnerabilities in its communications software with the release of software updates. "The updates were needed in order to fix two software problems, one of which can render a user vulnerable to a malicious attack if the user is duped into following web hyperlinks that are specially crafted to cause unwanted software to run."

"Skype proactively discloses and rates security issues when they arise so that its customers have the latest information about its software. In addition, Skype participates as a member in the international Forum of Incident Response and Security Teams, a global body that allows for rapid interchange of information among software vendors, government, business and network operators," it added. ®

Designing a Defense for Mobile Applications

More from The Register

next story
DARPA-derived secure microkernel goes open source tomorrow
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
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
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
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
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.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.