Context IS Advisory - .NET 1.0 through .NET 4 Remote Code Execution

[Context IS - Disclosure <disclosure () contextis co uk>]

===============================ADVISORY===============================
Systems Affected:    .NET 1.0 through .NET 4
Severity:            High
Category:            Remote Code Execution
Author:              Context Information Security
Reported to vendor:  17th March 2011
Advisory Issued:     8th May 2012
Reference:           CVE-2012-0160, CVE-2012-0161 
===============================ADVISORY===============================
 
Description
-----------
The Microsoft .NET framework (in all released versions) is vulnerable to a number of attacks through the misuse of 
binary serialization which could be leveraged to disclose important information or to achieve remote code execution. 
 
Analysis
--------
The .NET framework has a number of serialization mechanisms a developer can use to load and save object instances 
either to permanent storage locations or for use in the transport of objects across boundaries. Probably the most 
important of these is the IFormatter serializers, specifically BinaryFormatter which has existed in one form since the 
very first version of the framework. 
 
It is common to see this used as a mechanism for data storage, object marshalling and object cloning. This can lead to 
situations where an attacker can introduce malicious objects into an application either remotely over a network or 
through a sandboxed environment.
 
Through the use of specific functionality an attacker can then leverage this situation to circumvent security 
mechanisms and gain remote code execution without user interaction or to disclosure important information.
 
 
Technologies Affected
---------------------
Microsoft .Net Frameworks 1.0 through 4.0
 
Vendor Response
---------------
Microsoft advises users to patch the .Net Framework to the latest version.  See the following Microsoft security 
bulletin for more details:
http://technet.microsoft.com/en-us/security/bulletin/ms12-035
 
There are a number of mitigations which reduce the severity of the issues which are also detailed in Microsoft’s 
bulletin. 
 
Disclosure Timeline
-------------------
13th March 2011 – Vendor Notification
8th May 2012 – Vendor Patch Released
 
 
Credits
--------
James Forshaw of Context Information Security
 
 
About Context Information Security
----------------------------------
 Context was launched in 1998 and has a client base that includes some of the world’s most high profile blue chip 
companies, alongside government organisations. An exceptional level of technical expertise underpins all Context 
services, while a detailed and comprehensive approach helps clients to attain a deeper understanding of security 
vulnerabilities, threats or incidents. The company’s strong track record is based above all, on the technical skills, 
professionalism, independence and integrity of its consultants.   
 
Many of the world's most successful organisations turn to Context for technical assurance, incident response and 
investigation services. Context is also at the forefront of research and development in security technology.  As well 
as publishing white papers and blogs addressing current and emerging security threats and trends, Context consultants 
are frequently invited to present at open and closed industry events around the world. Context delivers a comprehensive 
portfolio of advanced technical services and with offices in the UK, Germany and Australia, is ideally placed to work 
with clients worldwide.  
 
Web:        www.contextis.com
Email:      disclosure () contextis com
 
 
 
 
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