Feeds

Microsoft issues doubleplus critical security fix

Secured Win 2003 systems among the vulnerable

  • alert
  • submit to reddit

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

Microsoft yesterday warned of a critical flaw affecting all versions of its operating systems bar Windows 98 and ME.

The critical vulnerability opens the way for crackers to run malicious code and take over vulnerable machines. The flaw affects Windows NT 4, NT 4 Terminal Edition, Win 2000, XP and Win 2003 (irrespective of any service pack applied). Redmond has issued a fix, which users are strongly urged to review.

The flaw, uncovered by Polish white hats Last Stage of Delirium (LSD), arises from a stack buffer overflow vulnerability within an integral component of Windows - an RPC interface implementing Distributed Component Object Model services (DCOM).

RPC provides an inter-process communication mechanism that allows a program running on one computer to seamlessly execute code on a remote system

Because of an implementation error in a function responsible for instantiation of DCOM objects, remote attackers can obtain remote access to vulnerable systems.

By sending specially crafted message to the TCP port 135 of vulnerable Windows system, an attacker can exploit the vulnerability and execute any code with system privileges. On intranets access to this port can easily be blocked by a properly configured firewall, but that still leaves enormous scope for mischief.

In an advisory LSD warns: "The impact of the vulnerability can be hardly overestimated. It affects every installation of the Windows NT/2K/XP/2003 operating system not protected by additional security mechanisms for access control, such as firewall systems.

"The vulnerability may also cause enormous harm if its exploitation would be conducted with the usage of even primitive worm technologies," it adds.

Members of the LSD Research Group were able to develop two fully functional proof of concept codes, respectively for Windows 2000/XP and Windows 2003 Server.

These exploits - which LSD has decided not to make public - work irrespective of the service pack a user might apply to the system. The vulnerability is also exploitable in the case of Windows 2003 Server, regardless of increased buffer overflow prevention mechanisms built into the latest version of Microsoft's OS. A noteworthy point, particularly when we remember how Microsoft went out its way to say the last Win 2003 patch that went out was really to fix an IE bug.

LSD warns: "Although exploitation of this vulnerability should not be considered as trivial, due to its potential impact, exploits codes from various sources may be expected in the wild very soon."

Microsoft advisory on the problem can be found here.

Wednesday night is, of course, patch issuing night for Microsoft. As well as a fix for the critical flaw detailed above, Redmond also posted fixes for two less serious vulnerabilities. These cover fixes for a flaw in ISA Server's error pages that could allow cross-site scripting attacks (advisory here) and an unchecked buffer in Windows Shell could enable system compromise of Win XP machines (advisory here).

Microsoft designates both fixes as important - and not critical - because although they might sound bad, the problems covered are in practice difficult to exploit. ®

Related Stories

IE bugs keep coming
Dell to tighten systems security
First Win 2003 patch is really for IE
MS withdraws XP security update

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

More from The Register

next story
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
BMW's ConnectedDrive falls over, bosses blame upgrade snafu
Traffic flows up 20% as motorway middle lanes miraculously unclog
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
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

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
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.
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.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.