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Exploited in the wildServers & business softwareWork IT

CVE-2017-8759 Microsoft .NET Framework: command or code injection

In plain words: The program treats text it receives as instructions instead of plain data. The attacker can run commands on the machine — often the whole device is taken over.

Confirmed exploited by CISA on · US federal patch deadline May 3, 2022

What to do

  1. Install Microsoft's security update for .NET Framework. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.

The details

Official name
Microsoft .NET Framework Remote Code Execution Vulnerability
Product
Microsoft .NET Framework
CISA description
Microsoft .NET Framework contains a remote code execution vulnerability when processing untrusted input that could allow an attacker to take control of an affected system.
Type of flaw
Command or code injection (CWE-20)
Confirmed exploited
Nov 3, 2021
US federal patch deadline
May 3, 2022

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Answering about CVE-2017-8759 ·

Questions about CVE-2017-8759

Is CVE-2017-8759 being exploited?

Yes. CISA added CVE-2017-8759 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2017-8759?

Install Microsoft's security update for .NET Framework. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.

Am I affected by CVE-2017-8759?

Only if you use Microsoft .NET Framework. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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