Microsoft .NET Framework CVE-2017-0248 Security Bypass Vulnerability

Description

Microsoft .NET Framework is prone to a security-bypass vulnerability. An attacker can exploit this issue to bypass certain security restrictions and perform unauthorized actions. This may aid in further attacks.

Technologies Affected

• Microsoft .NET Framework 2.0 SP2
• Microsoft .NET Framework 3.0
• Microsoft .NET Framework 3.5
• Microsoft .NET Framework 3.5.1
• Microsoft .NET Framework 4.5.2
• Microsoft .NET Framework 4.6
• Microsoft .NET Framework 4.6.1
• Microsoft .NET Framework 4.6.2
• Microsoft .NET Framework 4.7
• Microsoft Windows 10 Version 1607 for 32-bit Systems
• Microsoft Windows 10 Version 1607 for x64-based Systems
• Microsoft Windows 10 for 32-bit Systems
• Microsoft Windows 10 for x64-based Systems
• Microsoft Windows 10 version 1511 for 32-bit Systems
• Microsoft Windows 10 version 1511 for x64-based Systems
• Microsoft Windows 10 version 1703 for 32-bit Systems
• Microsoft Windows 10 version 1703 for x64-based Systems
• Microsoft Windows 7 for 32-bit Systems SP1
• Microsoft Windows 7 for x64-based Systems SP1
• Microsoft Windows 8.1 for 32-bit Systems
• Microsoft Windows 8.1 for x64-based Systems
• Microsoft Windows RT 8.1
• Microsoft Windows Server 2008 R2 Datacenter SP1
• Microsoft Windows Server 2008 R2 for Itanium-based Systems SP1
• Microsoft Windows Server 2008 R2 for x64-based Systems SP1
• Microsoft Windows Server 2008 for 32-bit Systems SP2
• Microsoft Windows Server 2008 for Itanium-based Systems SP2
• Microsoft Windows Server 2008 for x64-based Systems SP2
• Microsoft Windows Server 2012
• Microsoft Windows Server 2012 R2
• Microsoft Windows Server 2016

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of exploits.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.

Communicate sensitive information through secure means.
Use multiple layers of encryption when communicating sensitive information between a client and a server. This will reduce the chance of a successful exploit.

Updates are available. Please see the references or vendor advisory for more information.