Microsoft Server Message Block 3.1.1 (SMBv3) Protocol Vulnerability

[engine]

Microsoft has issued a guidance for disabling Server Message Block 3.1.1 (SMBv3) protocol over a vulnerability where it would give the ability to execute code on the target SMB Server or SMB Client.

There is a workaround, which includes disabling SMBv3 compression, and is detailed in the advisory.

[portal.msrc.microsoft.com...]

[lammert]

(...) the vulnerability exists in a new feature that was added to Windows 10 version 1903. Older versions of Windows do not support SMBv3.1.1 compression.

This is yet another problem introduced with a recent update, rather than an existing problem which was just discovered recently. There is a serious issue at Microsoft in validating their new software development and update procedures.

[engine]

Microsoft has release an out of band update to patch the vulnerability exposed earlier this week.

The fix is available as KB4551762, an update for Windows 10, versions 1903 and 1909, and Windows Server 2019, versions 1903 and 1909.

The update fixes CVE-2020-0796 (SMBGhost), a vulnerability in Server Message Block, a protocol for sharing files, printers, and other resources on local networks and the Internet.

[zdnet.com...]