CVE-2021-21272

ORAS is open source software which enables a way to push OCI Artifacts to OCI Conformant registries. ORAS is both a CLI for initial testing and a Go Module.

In ORAS from version 0.4.0 and before version 0.9.0, there is a "zip-slip" vulnerability.

The directory support feature allows the downloaded gzipped tarballs to be automatically extracted to the user-specified directory where the tarball can have symbolic links and hard links.

A well-crafted tarball or tarballs allow malicious artifact providers linking, writing, or overwriting specific files on the host filesystem outside of the user-specified directory unexpectedly with the same permissions as the user who runs `oras pull`.

Users of the affected versions are impacted if they are `oras` CLI users who runs `oras pull`, or if they are Go programs, which invoke `github.com/deislabs/oras/pkg/content.FileStore`.

The problem has been fixed in version 0.9.0.

For `oras` CLI users, there is no workarounds other than pulling from a trusted artifact provider.

For `oras` package users, the workaround is to not use `github.com/deislabs/oras/pkg/content.FileStore`, and use other content stores instead, or pull from a trusted artifact provider.