Security Advisory 2021-11

Summary Local privilege escalation in Octopus Tentacle (CVE-2021-31822)
Advisory Number 2021-11
Discovery Date 31 Aug 2021
Patch Release Date 08 Nov 2021
Advisory Release Date 24 Nov 2021
Product Octopus Tentacle
Operating System Linux
Severity High
CVE ID CVE-2021-31822

Customers who have upgraded Octopus Tentacle to version 6.1.1116 or higher are not affected.

Severity

Octopus Deploy has given this vulnerability a high rating. This rating was given according to the Octopus Deploy security levels, which ranks vulnerabilities as critical, high, medium, or low severity.

This is our assessment and you should evaluate its applicability to your own environment.

Details

When Octopus Tentacle is installed on a Linux operating system, the systemd service file permissions are misconfigured. This could lead to a local unprivileged user modifying the contents of the systemd service file to gain privileged access.

All versions of Octopus Tentacle are affected by this vulnerability.

Fix

To address this vulnerability, we have released Octopus Tentacle version:

  • 6.1.1116

The latest versions of Octopus Deploy products can be downloaded from https://octopus.com/downloads and previous versions can be downloaded from https://octopus.com/downloads/previous

What You Need to Do

Octopus Deploy recommends that you upgrade to the latest version (6.1.1116). You can download the latest version of from https://octopus.com/downloads

If you can't upgrade to the latest version (6.1.1116):

If you have feature version... ...then upgrade to this version
3.x or greater 6.1.1116

For Octopus Tentacle versions before 3.x please contact our support team (https://octopus.com/support ) for advice on upgrading to the latest version.

Mitigation

The file permissions for the systemd unit file can be manually updated to “644" by using the "chmod" command. The installation location for the Tentacle systemd unit file is:

1/etc/systemd/system/<Name of Tentacle instance (default Tentacle)>.service

For the default Tentacle instance name the mitigation is:

1chmod 644 /etc/systemd/system/Tentacle.service

Support

If you have any questions or concerns regarding this advisory, please contact our support team (https://octopus.com/support).

Exploitation and Public Announcements

The Octopus Deploy security team is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

This vulnerability was found by an Octopus Deploy customer.