Security for the stub uploader is of the highest importance. If the stub uploader gets compromised, an attacker could upload manipulated stub packages to gain full access to developer machines or even production hosts. Considering the high trust, quick turnaround, and automated installation of stub packages, this could have significant security implications.

Only a small number of typeshed maintainers have commit rights for this repository to minimize the attack vector in case of hacked accounts. This is also the reason that this repository is part of a separate GitHub organization and not the python or psf organizations, like typeshed is.

Typeshed maintainers without commit rights are still considered maintainers of the stub uploader and are encouraged to manage issues and send and review pull requests.

To ensure that a compromised typeshed repository can't lead to compromised stub packages, all typeshed data is verified by the stub uploader before building packages. The stub uploader ensures that only stub and metadata files are added to the stub packages. This also means that no code from the typeshed repository must be executed while building packages, and no modules must be imported.

Another possible attack vector is dependencies of stub packages. A compromised dependency can have a similar effect to when a stub package gets compromised directly. Therefore, only certain dependencies are allowed:

• Dependencies on other stub packages created by typeshed.
• Dependencies on packages the upstream package depends on – even recursively. Since it's likely that a stub package gets installed alongside the upstream package, this does not introduce an additional security liability.
• Dependencies that are explicitly allowlisted in the stub uploader. These dependencies are vetted to be from a trusted source.

Stub packages are uploaded to PyPI by the PyPI user typeshed_bot using an API token. The packages are owned solely by that user, so that no other PyPI user can upload new versions of the packages, in case the PyPI account of a maintainer becomes compromised.

To report an issue, go to https://github.com/typeshed-internal/stub_uploader/security. We commit to respond to any issue within 14 days and promptly fix any problems.