Microsoft Windows Communication Foundation (WCF) And Windows Identity Foundation (WIF) SAML Token Authentication Bypass Vulnerability

Summary

An authentication bypass vulnerability exists in Windows Communication Foundation (WCF) and Windows Identity Foundation (WIF), allowing signing of SAML tokens with arbitrary symmetric keys. This vulnerability allows an attacker to impersonate another user, which can lead to elevation of privileges. The vulnerability exists in WCF, WIF 3.5 and above in .NET Framework, WIF 1.0 component in Windows, WIF Nuget package, and WIF implementation in SharePoint.

Credit:

The information has been provided by Oleksandr Mirosh (@olekmirosh) and Alvaro Munoz (@pwntester)

The original article can be found at:

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1006

 


Details

An unauthenticated attacker can exploit this by signing a SAML token with any arbitrary symmetric key.

Vulnerable Systems:
Microsoft .NET Framework 4.7.2
Microsoft .NET Framework 4.7.1
Microsoft .NET Framework 4.6.2
Microsoft .NET Framework 4.6.1
Microsoft .NET Framework 3.5.1
Microsoft .NET Framework 4.8
Microsoft .NET Framework 4.7
Microsoft .NET Framework 4.6
Microsoft .NET Framework 4.5.2
Microsoft .NET Framework 3.5
Microsoft .NET Framework 3.0 SP2
Microsoft .NET Framework 2.0 SP2

CVE Information:

CVE-2019-1006

Disclosure Timeline:
Published Date:07/16/2019