Risk
12/22/2010
10:51 PM
George V. Hulme
George V. Hulme
Commentary
Connect Directly
RSS
E-Mail
50%
50%

Microsoft Moves To Block Zero Day Attack

A French IT security firm recently warned of a new vulnerability that opens most versions of Microsoft Internet Explorer open to attack.

A French IT security firm recently warned of a new vulnerability that opens most versions of Microsoft Internet Explorer open to attack.Should a successful hack be launched, the attacker could circumvent many of the defenses available in both Windows Vista and Windows 7. The attacker could also run code of their choice on the target system.

To make the situation more pressing, the Metasploit project recently added an exploit to its database that successfully evades Microsoft's ASLR (Address Space Layout Randomization) and bypass DEP (Data Execution Prevention) defenses.

In an e-mail to InformationWeek, Microsoft noted that there is currently no indication that customers are being attacked. Late this evening, Microsoft's Security Research & Defense blog posted an update and mitigation guidance for the vulnerability.

Microsoft provided some details on the exploit:

The Metasploit project recently published an exploit for this vulnerability using a known technique to evade ASLR (Address Space Layout Randomization) and bypass DEP (Data Execution Prevention).

In a few words, Internet Explorer loads mscorie.dll, a library that was not compiled with /DYNAMICBASE (thus not supporting ASLR and being located always at the same base) when processing some html tags. Attackers use these predictable mappings to evade ASLR and bypass DEP by using ROP (return oriented programming) gadgets from these DLLs in order to allocate executable memory, copying their shellcode and jumping into it. Note that without that predictable mapping, the only public ways to evade ASLR and DEP is through:

• Use of this (in case the current vulnerability allows) or another vulnerability as an information leak.

• Using techniques such as JIT-spraying or similar ones. Please note IE only JITs IE9's javascript and there are security mitigations in place. But third party plugins could JIT in an insecure manner.

The same post recommends users employ Enhanced Mitigation Experience Toolkit (EMET) to block the threat. According to Microsoft, by using EMET, the associated mandatory ASLR, Heap Spray pre-allocation, and EAT Filtering will all mitigate the risk associated with this attack.

Microsoft also has more information in Security Advisory 2488013.

For my security and technology tweets throughout the day, find me on Twitter.

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Flash Poll
Current Issue
Cartoon
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-0761
Published: 2014-08-27
The DNP3 driver in CG Automation ePAQ-9410 Substation Gateway allows remote attackers to cause a denial of service (infinite loop or process crash) via a crafted TCP packet.

CVE-2014-0762
Published: 2014-08-27
The DNP3 driver in CG Automation ePAQ-9410 Substation Gateway allows physically proximate attackers to cause a denial of service (infinite loop or process crash) via crafted input over a serial line.

CVE-2014-2380
Published: 2014-08-27
Schneider Electric Wonderware Information Server (WIS) Portal 4.0 SP1 through 5.5 uses weak encryption, which allows remote attackers to obtain sensitive information by reading a credential file.

CVE-2014-2381
Published: 2014-08-27
Schneider Electric Wonderware Information Server (WIS) Portal 4.0 SP1 through 5.5 uses weak encryption, which allows local users to obtain sensitive information by reading a credential file.

CVE-2014-3344
Published: 2014-08-27
Multiple cross-site scripting (XSS) vulnerabilities in the web framework in Cisco Transport Gateway for Smart Call Home (aka TG-SCH or Transport Gateway Installation Software) 4.0 allow remote attackers to inject arbitrary web script or HTML via unspecified parameters, aka Bug IDs CSCuq31129, CSCuq3...

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
This episode of Dark Reading Radio looks at infosec security from the big enterprise POV with interviews featuring Ron Plesco, Cyber Investigations, Intelligence & Analytics at KPMG; and Chris Inglis & Chris Bell of Securonix.