Actively exploited in the wild. Patch or mitigate immediately — don't wait for a maintenance window.
An unauthenticated attacker, remotely over the network, with no user interaction, can fully compromise the system — steal data, tamper with it and take it offline.
A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.
Inferred from the weakness type (CWE) and how the flaw is reached — the techniques an attacker would chain to exploit this. Real-world corroboration appears here as threat intel is folded in.
Corroborated threat activity referencing this CVE — with source and confidence, not inference.
Named threat actors and observed ATT&CK techniques appear here as intel feeds are folded in — the ATT&CK chain above stays inferred until then.
Generated by Wavense from the CVE record — an immediate mitigation and the permanent fix.
To immediately reduce risk, block TCP port 445 at the perimeter firewall to prevent external exploitation of servers. Temporarily disable SMBv3 compression on affected Windows servers via PowerShell to prevent exploitation of the server-side vulnerability. Implement strong network segmentation to restrict SMB traffic to only trusted devices and necessary internal subnets.
Apply the official security update from Microsoft (KB4551762 or later superseding updates) for CVE-2020-0796 as soon as possible. This vulnerability affects Windows 10 versions 1903 and 1909, and Windows Server versions 1903 and 1909, among others. Ensure all relevant Windows systems are updated to a patched version to permanently resolve the vulnerability and restore secure SMB functionality.
An unauthenticated attacker can execute arbitrary code on a vulnerable SMBv3 server or client by sending specially crafted SMBv3 packets. This allows for full system compromise, leading to data theft, system disruption, or complete control over the affected machine and potential lateral movement within the network. The business consequences include significant operational downtime, severe data breaches, and reputational damage.
Other CVEs affecting windows 10 1903
Active Directory Domain Services Elevation of Privilege Vulnerability
Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents. An attacker could craft a malicious ActiveX control to be used by a Microsoft Office document that hosts the browser rendering engine. The attacker would then have to convince the user to open the malicious document. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Microsoft Defender Antivirus and Microsoft Defender for Endpoint both provide detection and protections for the known vulnerability. Customers should keep antimalware products up to date. Customers who utilize automatic updates do not need to take additional action. Enterprise customers who manage updates should select the detection build 1.349.22.0 or newer and deploy it across their environments. Microsoft Defender for Endpoint alerts will be displayed as: “Suspicious Cpl File Execution”. Upon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs. Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability. UPDATE September 14, 2021: Microsoft has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. Please see the FAQ for important information about which updates are applicable to your system.
A remote code execution vulnerability exists in Microsoft Windows when the Windows Adobe Type Manager Library improperly handles a specially-crafted multi-master font - Adobe Type 1 PostScript format.For all systems except Windows 10, an attacker who successfully exploited the vulnerability could execute code remotely, aka 'Adobe Font Manager Library Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-0938.
A remote code execution vulnerability exists in the way that the Windows Graphics Device Interface (GDI) handles objects in the memory, aka 'GDI+ Remote Code Execution Vulnerability'.
Microsoft DWM Core Library Elevation of Privilege Vulnerability
A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates.An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source, aka 'Windows CryptoAPI Spoofing Vulnerability'.