8.8High
Microsoft Remote Desktop Client
CVE-2021-34535
Remote Desktop Client Remote Code Execution Vulnerability
What this means for your business
- It affects Microsoft Remote Desktop Client. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
- FIRST's prediction model gives it a 22% chance of attack attempts being seen in the next 30 days, ranking above 97% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Microsoft Remote Desktop Client, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 8.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H- Assigned by
- secure@microsoft.com
Dates
- Published
- 2021-08-12
- Last modified
- 2026-08-10
- Sources
- NVD
Affected products
- Microsoft Remote Desktop Clientall versions
- Microsoft Windows 10all versions, 20h2, 21h1, 1607, 1809, 1909, 2004
- Microsoft Windows 7all versions
- Microsoft Windows 8.1all versions
- Microsoft Windows Rt 8.1all versions
- Microsoft Windows Server 2008r2
- Microsoft Windows Server 2012all versions, r2
- Microsoft Windows Server 2016all versions
- Microsoft Windows Server 2019all versions
As listed in the NVD configuration data. Not a statement about your estate.