[Solved] Authentication error function not supported

The problem

You can get this error while trying to open an RDP session.

An authentication error has occurred.
The function requested is not supported

An authentication error has occurred the function requested is not supported

The reason

This is due to a combination of three factors:

  • You activated NLA on your target computer
  • The target computer is not patched for CVE-2018-0886
  • You enforced the Force updated clients or Mitigated parameters on the source computer

The solution

Choose one of the following and see links in the More about section below if you don’t know how to do it.

  • Disable NLA on your target computer (Not recommended)
  • Patch your target computer for CVE-2018-0886 (Recommended)
  • Enforced the Vulnerable parameter on the source computer (Not recommended)

More about

Why Use Network Level Authentication (Technet)

WS2008: Network Level Authentication and Encryption (Microsoft blogs)

Configuring Network Level Authentication for RDP

CredSSP updates for CVE-2018-0886 (Microsoft Support)

CVE-2018-0886 | CredSSP Remote Code Execution Vulnerability (Microsoft Security Portal)

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s