Feeds

Windows plagued by 17-year-old privilege escalation bug

All 32-bit versions vulnerable

Build a business case: developing custom apps

A security researcher at Google is recommending computer users make several configuration changes to protect themselves against a previously unknown vulnerability that allows untrusted users to take complete control of systems running most versions of Microsoft Windows.

The vulnerability resides in a feature known as the Virtual DOS Machine, which Microsoft introduced in 1993 with Windows NT, according to this writeup penned by Tavis Ormandy of Google. Using code written for the VDM, an unprivileged user can inject code of his choosing directly into the system's kernel, making it possible to make changes to highly sensitive parts of the operating system.

"You can in theory write to memory segments that are otherwise considered highly trusted and sensitive," said Tom Parker, a director in the security consulting services group at Securicon, a Washington, DC-based security practice. "So for example, malware could possibly use it to install a key logger."

The vulnerability exists in all 32-bit versions of Microsoft OSes released since 1993, and proof-of-concept code works on the XP, Server 2003, Vista, Server 2008, and 7 versions of Windows, Ormandy reported. Presumably, Windows 2000 is also susceptible. Immunity, a Miami-based company that makes auditing software for security professionals, has already added a module exploiting the vulnerability to its product called Canvas. The exploit has been tested on all versions of Windows except for 3.1.

Ormandy said the security hole can easily be closed by turning off the MSDOS and WOWEXEC subsystems. The changes generally don't interfere with most tasks since they disable rarely-used 16-bit applications. He said he informed Microsoft security employees of the vulnerability in June.

"Regrettably, no official patch is currently available," he wrote. "As an effective and easy to deploy workaround is available, I have concluded that it is in the best interest of users to go ahead with the publication of this document without an official patch."

Microsoft security officials - who are already working double-duty responding to a potent Internet Explorer bug used to attack Google - said they are looking in to Ormandy's advisory and are not aware of attacks that target the reported vulnerability. ®

The essential guide to IT transformation

More from The Register

next story
Rupert Murdoch says Google is worse than the NSA
Mr Burns vs. The Chocolate Factory, round three!
Microsoft cries UNINSTALL in the wake of Blue Screens of Death™
Cache crash causes contained choloric calamity
e-Borders fiasco: Brits stung for £224m after US IT giant sues UK govt
Defeat to Raytheon branded 'catastrophic result'
Germany 'accidentally' snooped on John Kerry and Hillary Clinton
Dragnet surveillance picks up EVERYTHING, USA, m'kay?
Know what Ferguson city needs right now? It's not Anonymous doxing random people
U-turn on vow to identify killer cop after fingering wrong bloke
Snowden on NSA's MonsterMind TERROR: It may trigger cyberwar
Plus: Syria's internet going down? That was a US cock-up
Who needs hackers? 'Password1' opens a third of all biz doors
GPU-powered pen test yields more bad news about defences and passwords
Think crypto hides you from spooks on Facebook? THINK AGAIN
Traffic fingerprints reveal all, say boffins
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
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.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.