In NGINX Controller versions prior to 3.2.0, an unauthenticated attacker with network access to the Controller API can create unprivileged user accounts. The user which is created is only able to upload a new license to the system but cannot view or modify any other components of the system. (CVE-2020-5863)

Impact

Attackers can exploit this vulnerability to create user accounts with limited access and to create a denial of service (DoS) scenario on the NGINX Controller.

F5 Product Development has assigned ID IND-9428 (NGINX Controller) to this vulnerability.

To determine if your product and version have been evaluated for this vulnerability, refer to the Applies to (see versions) box. To determine if your release is known to be vulnerable, the components or features that are affected by the vulnerability, and for information about releases, point releases, or hotfixes that address the vulnerability, refer to the following table. For more information about security advisory versioning, refer to K51812227: Understanding Security Advisory versioning.

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If you are running a version listed in the Versions known to be vulnerable column, you can eliminate this vulnerability by upgrading to a version listed in the Fixes introduced in column. If the table lists only an older version than what you are currently running, or does not list a non-vulnerable version, then no upgrade candidate currently exists.

Mitigation

To mitigate this vulnerability, you can restrict network access to the NGINX Controller API port (TCP 443) by configuring either the NGINX Controller’s host firewall software or an external packet filtering device to allow only trusted networks to access the NGINX Controller API.

Important: The NGINX Controller should be deployed on a secure, internal network only. F5 strongly recommends against exposing the NGINX Controller API to the internet. For more information, refer to the Prerequisites section of NGINX Controller Installation Guide v3

Note: For more information on other required firewall / IP settings on the NGINX Controller, refer to the Firewall / IP Settings section in Tech Specs for NGINX Controller and Controller Agent.

• K51812227: Understanding Security Advisory versioning
• K41942608: Overview of Security Advisory articles
• K4602: Overview of the F5 security vulnerability response policy
• K4918: Overview of the F5 critical issue hotfix policy
• K167: Downloading software and firmware from F5
• K9970: Subscribing to email notifications regarding F5 products
• K9957: Creating a custom RSS feed to view new and updated documents