Security Advisory 2021-09
|Summary||Remote Code Execution in Octopus Server (CVE-2021-31819)|
|Discovery Date||21 Jul 2021|
|Patch Release Date||02 Sep 2021|
|Advisory Release Date||22 Sep 2021|
|Operating System||Linux and Windows|
Customers who have downloaded and installed any of the Octopus Server versions listed below ("Details") are affected.
Please upgrade your Octopus Server immediately to fix this vulnerability.
Customers who have upgraded Octopus Server to version 2021.2.7428 or higher are not affected.
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.
Octopus Server uses Halibut as its communication framework. There was a deserialisation vulnerability discovered in Halibut which could allow remote code execution on Octopus Server from a trusted tentacle.
The versions of Octopus Server affected by this vulnerability are:
All 0.x.x, 1.x.x, 2.x.x, 3.x.x, 4.x.x versions
All 2018.x.x, 2019.x.x, 2020.1.x, 2020.2.x, 2020.3.x, 2020.4.x, 2020.5.x versions
All 2020.6.x versions before 2020.6.5394
All 2021.1.x versions before 2021.1.7738
All 2021.2.x versions before 2021.2.7428
To address this vulnerability, we have released Octopus Server versions:
What You Need to Do
Octopus Deploy recommends that you upgrade to the latest version (2021.2.7428). You can download the latest version of
If you can't upgrade to the latest version (2021.2.7428):
|If you have feature version...||...then upgrade to this version|
|2018.x.x, 2019.x.x, 2020.1.x, 2020.2.x, 2020.3.x, 2020.4.x, 2020.5.x||2020.6.5394|
For Octopus Server versions: 0.xx, 1.x.x, 2.x.x, 3.x.x, 4.x.x please contact our support team (https://octopus.com/support) for advice on upgrading to a supported version.
There is no known mitigation for CVE-2021-31819, it is important to upgrade to a fixed version as soon as possible.
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.