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  3. CVE-2017-9805
Exploited in the wildServers & business softwareWork IT

CVE-2017-9805 Apache Struts: unsafe data loading

In plain words: The program unpacks saved data from outside without checking it is safe. Usually lets an attacker run code on the server.

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

What to do

  1. Install Apache's security update for Struts. 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
Apache Struts Deserialization of Untrusted Data Vulnerability
Product
Apache Struts
CISA description
Apache Struts REST Plugin uses an XStreamHandler with an instance of XStream for deserialization without any type filtering, which can lead to remote code execution when deserializing XML payloads.
Type of flaw
Unsafe data loading (CWE-502)
Confirmed exploited
Nov 3, 2021
US federal patch deadline
May 3, 2022

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Answering about CVE-2017-9805 ·

Questions about CVE-2017-9805

Is CVE-2017-9805 being exploited?

Yes. CISA added CVE-2017-9805 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-2017-9805?

Install Apache's security update for Struts. 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-2017-9805?

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

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