Check Point Advisories

Plex Media Server Distributed Denial of Service (CVE-2021-33959)

Vulnerability
Protection

Check Point Reference:	CPAI-2021-2281
Date Published:	19 Jan 2025
Severity:	High
Last Updated:	Sunday 19 January, 2025
Source:
Industry Reference:	CVE-2021-33959
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Plex Media Server v1.21 and prior
Vulnerability Description	A Distributed Denial of Service reflection vulnerability exists in Plex Media Server. Successful exploitation of this vulnerability could result in a denial of service into the Third party victim.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the Plex Media Server Distributed Denial of Service (CVE-2021-33959) protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Application Servers Protection Violation.
Attack Information: Plex Media Server Distributed Denial of Service (CVE-2021-33959)