Coastal Network Status

South Carolina Information Sharing and Analysis Center

SC INFORMATION SHARING AND ANALYSIS CENTER BULLETIN

DATE ISSUED: 2/12/2013

SUBJECT: Vulnerability in .NET Framework Could Allow Elevation of Privilege

OVERVIEW:

A vulnerability has been discovered in the Microsoft .NET Framework which could allow an attacker to take complete control of an affected system. Microsoft.NET is a software framework for applications designed to run under Microsoft Windows. This vulnerability can be exploited if a user visits or is redirected to a malicious web page or runs a specially crafted Microsoft.NET application.

Successful exploitation of this vulnerability could allow an attacker to obtain complete control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

DESCRIPTION:

An elevation of privilege vulnerability exists in the way that the .NET Framework elevates the permissions of a callback function when a particular Windows Forms object is created. Exploitation could occur if a user visits a specially crafted website that hosts malicious XBAP (Extensible Application Markup Language Browser Application) content using a web browser capable of instantiating XBAPs. Additionally, an attacker can exploit this issue by creating a specially crafted Windows .NET application to bypass Code AccessSecurity (CAS) restrictions.

An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

SYSTEM AFFECTED:

Microsoft .NET Framework 2.0
Microsoft .NET Framework 3.5 (except SP1)
Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4
Microsoft .NET Framework 4.5 (except on Windows RT)

RISK:

Government:

Large and medium government entities: High

Small government entities: High

Businesses:

Large and medium business entities: High

Small business entities: High

Home users: High

RECOMMENDATIONS:

We recommend the following actions be taken:

Apply appropriate patches provided by Microsoft to vulnerable systems immediately after appropriate testing.
Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources. (Macintosh).

REFERENCES:

Microsoft:

http://technet.microsoft.com/en-us/security/bulletin/ms13-015

CVE:

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-0073

SecurityFocus:

http://www.securityfocus.com/bid/57847

Please feel free to contact the SC ISAC if you have any questions or need any additional information.

The SC ISAC will provide amplifying information as it becomes available.

SC-ISAC Contact Information

Email: SC-ISAC@cio.sc.gov

SC ISAC Security Line: 803-896-1650

24-hour hotline: +1 803-896-0001

Fax: +1 803-896-0375

Postal address:

SC-ISAC

DSIT Budget and Control Board

4430 Broad River Road

Columbia S.C. 29210

SC-ISAC is available via hotline 08:00-17:00 EST (GMT-5)/ EDT (GMT-4)

Monday through Friday

Using Encryption

We strongly urge you to encrypt sensitive information sent by email. Our

public PGP key is available from:

https://sc-isac.sc.gov/public.key

NO WARRANTY

Any material furnished by SC-ISAC is furnished on an "as is" basis.

SC-ISAC makes no warranties of any kind, either expressed or implied as to

any matter including, but not limited to, warranty of fitness for a particular

purpose or merchantability, exclusivity or results obtained from use of the

material. SC-ISAC does not make any warranty of any kind with respect to