Word leaked out on Tuesday of a new vulnerability in recent versions of Windows that has the potential to unleash the kind of self-replicating attacks that allowed the WannaCry and NotPetya worms to cripple business networks around the world.
ARS TECHNICA
This story originally appeared on Ars Technica, a trusted source for technology news, tech policy analysis, reviews, and more. Ars is owned by WIRED’s parent company, Condé Nast.
The vulnerability exists in version 3.1.1 of the Server Message Block 3.1.1 that’s used to share files, printers, and other resources on local networks and over the internet. Attackers who successfully exploit the flaw can execute code of their choice on both servers and end-user computers that use the vulnerable protocol, Microsoft said in this bare-bones advisory.
The flaw, which is tracked as CVE-2020-0796, affects Windows 10 and Windows Server 2019, which are relatively new releases that Microsoft has invested huge amounts of resources hardening against precisely these types of attacks. Patches aren’t available, and Tuesday’s advisory gave no timeline for one being released. Asked if there was a timeline for releasing a fix, a Microsoft representative said: “Beyond the advisory you linked, nothing else to share from Microsoft at this time.”
In the meantime, Microsoft said vulnerable servers can be protected by disabling compression to block unauthenticated attackers from exploiting the vulnerability against an SMBv3 server. Users can use the following PowerShell command to turn off compression without needing to reboot the machine:
Set-ItemProperty -Path “HKLM:SYSTEMCurrentControl