CVE-2020-27195 Use After Free in HashiCorp Nomad

Critical 9.1 Published 22 Oct 2020 Updated 4 Aug 2024

Attackers can bypass the client file sandbox in HashiCorp Nomad using template or artifact stanzas to access or modify files outside the intended directory.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2020-27195?

CVE-2020-27195 is a critical path traversal vulnerability in n/a, published on 22 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

HashiCorp Nomad and Nomad Enterprise version 0.9.0 up to 0.12.5 client file sandbox feature can be subverted using either the template or artifact stanzas. Fixed in 0.12.6, 0.11.5, and 0.10.6

Which versions are affected by CVE-2020-27195?

7 open source packages ship an affected version, including github.com/hashicorp/nomad. It affects 1 product.

Package	Affected	Fixed in
`github.com/hashicorp/nomad` Go	From `0.11.0`	`0.11.5`
`github.com/hashicorp/nomad` Go	From `0.11.0`	`0.11.5`
`github.com/hashicorp/nomad` Go	From `0.12.0`	`0.12.6`
`github.com/hashicorp/nomad` Go	From `0.12.0`	`0.12.6`
`github.com/hashicorp/nomad` Go	From `0.9.0`	`0.10.6, 0.11.5, 0.12.6`
`github.com/hashicorp/nomad` Go	From `0.9.0`	`0.10.6`

1 more packages

github.com/hashicorp/nomad Go From 0.9.0 0.10.6

Products include Hashicorp Nomad.

How do I fix CVE-2020-27195?

Upgrade github.com/hashicorp/nomad to a fixed version for your release line: 0.11.5, 0.12.6 or 0.10.6.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2020-27195 being exploited?

There is no known exploitation of CVE-2020-27195 in the wild and no public exploit code.

Sources

Also known as GHSA-77cr-6gr8-7rr9, GO-2022-0806, UBUNTU-CVE-2020-27195.