2021-08 - Remote Code Execution via Deserialisation in the Halibut Protocol (CVE-2021-31819)
Patch Release Date
Advisory Release Date
Projects that have upgraded Halibut to version 4.4.7 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.
In Halibut versions prior to 4.4.7 there is a deserialisation vulnerability that could allow remote code execution on systems that already trust each other based on certificate verification.
The versions of Halibut affected by this vulnerability are:
All versions of Halibut before version 4.4.7.
To address this vulnerability, we have released Halibut version:
4.4.7 which contains a fix for this issue.
If you are using Halibut in your projects please update Halibut to the latest version which can downloaded from
What You Need to Do
Octopus Deploy recommends that you upgrade to the latest version (4.4.7). You can download the latest version of Halibut from
There are no known mitigations 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.
This vulnerability was discovered by Ashley Donaldson from Beyond Binary.
|Current Version (v. 8)||Sep 21, 2021 03:54||@a user|
|v. 7||Sep 15, 2021 04:03||@a user|
|v. 6||Sep 15, 2021 03:59||@a user|
|v. 5||Sep 15, 2021 01:12||@a user|
|v. 4||Sep 15, 2021 00:52||@a user|
|v. 3||Sep 15, 2021 00:34||@a user|
|v. 2||Sep 15, 2021 00:02||@a user|
|v. 1||Sep 15, 2021 00:02||@a user|