Information disclosure in .NET Framework

1) Information disclosure in .NET Framework

EUVDB-ID: #VU123

Risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-3255

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote attacker to read arbitrary files on vulnerable system.

The vulnerability exists due to an error when parsing XML files. A remote attacker, who can supply specially crafted XML file, containing a reference to an external entity, can read arbitrary files on vulnerable system via an XML external entity declaration.

Successful exploitation of this vulnerability may allow a remote attacker to read contents of arbitrary files on vulnerable system.

Mitigation

To resolve this vulnerability vendor recommends installing the following updates:

Windows Vista Service Pack 2

Microsoft .NET Framework 2.0 Service Pack 2
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6

Windows Vista x64 Edition Service Pack 2

Microsoft .NET Framework 2.0 Service Pack 2
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6

Windows Server 2008 for 32-bit Systems Service Pack 2

Microsoft .NET Framework 2.0 Service Pack 2
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6

Windows Server 2008 for x64-based Systems Service Pack 2

Microsoft .NET Framework 2.0 Service Pack 2
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6

Windows Server 2008 for Itanium-based Systems Service Pack 2

Microsoft .NET Framework 2.0 Service Pack 2

Windows 7 for 32-bit Systems Service Pack 1

Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows 7 for x64-based Systems Service Pack 1

Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2008 R2 for x64-based Systems Service Pack 1

Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1

Microsoft .NET Framework 3.5.1

Windows 8.1 for 32-bit Systems

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows 8.1 for x64-based Systems

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2012

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2012 R2

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows RT 8.1

Use Windows Update to obtain patch.

Windows 10

Microsoft .NET Framework 3.5/4.6

Windows 10 Version 1511

Microsoft .NET Framework 3.5/4.6.1

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2012 (Server Core installation)

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

Windows Server 2012 R2 (Server Core installation)

Microsoft .NET Framework 3.5
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 4.6/4.6.1

 

Vulnerable software versions

Microsoft .NET Framework: 2.0 Service Pack 2 - 4.6.1

External links

http://technet.microsoft.com/en-us/library/security/MS16-091

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.