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Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVE-2021-21272

Severity High
Score 7.7/10

Summary

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.

  • LOW
  • NETWORK
  • HIGH
  • CHANGED
  • NONE
  • LOW
  • NONE
  • NONE

CWE-22 - Path Traversal

Path traversal (or directory traversal), is a vulnerability that allows malicious users to traverse the server's root directory, gaining access to arbitrary files and folders such as application code & data, back-end credentials, and sensitive operating system files. In the worst-case scenario, an attacker could potentially execute arbitrary files on the server, resulting in a denial of service attack. Such an exploit may severely impact the integrity, confidentiality, and availability of an application.

Advisory Timeline

  • Published