CVE-2021-32635

Description

### Impact Due to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. ### Patches All users should upgrade to Singularity 3.7.4 or later. A patch was applied at: https://github.com/sylabs/singularity/commit/d52ae9d13979733c5e987a566fae59ed6f1bf796 ### Workarounds Users who only interact with the default remote endpoint are not affected. Installations with an execution control list configured to restrict execution to containers signed with specific secure keys are not affected. ### For more information General questions about the impact of the advisory can be asked in the: - [SingularityCE Slack Channel](https://singularityce.slack.com) - [SingularityCE Mailing List](https://groups.google.com/g/singularity-ce) Any sensitive security concerns should be directed to: security@sylabs.io See our Security Policy here: https://sylabs.io/security-policy

How to fix CVE-2021-32635

To remediate CVE-2021-32635, upgrade the affected package to a fixed version below.

• —upgrade to 3.7.4 or later

Is CVE-2021-32635 being exploited?

Low — EPSS is 0.6%, meaning exploitation activity has not been observed at scale.

Affected packages (1)

• >= 3.7.2, < 3.7.4