hpcng/singularity: Singularity 3.7.3

Singularity 3.7.3 is a security release. We recommend all users upgrade to this version.

• CVE-2021-29136: A dependency used by Singularity to extract docker/OCI image layers can be tricked into modifying host files by creating a malicious layer that has a symlink with the name "." (or "/"), when running as root. This vulnerability affects a singularity build or singularity pull as root, from a docker or OCI source.

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/hpcng/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!

Please use the singularity-3.7.3.tar.gz download below to obtain and install Singularity 3.7.3. The GitHub auto-generated 'Source Code' downloads do not include required dependencies etc.