CVE-2021-32643StaticFile.fromUrl can leak presence of a directory

Official description

Http4s is a Scala interface for HTTP services. `StaticFile.fromUrl` can leak the presence of a directory on a server when the `URL` scheme is not `file://`, and the URL points to a fetchable resource under its scheme and authority. The function returns `F[None]`, indicating no resource, if `url.getFile` is a directory, without first checking the scheme or authority of the URL. If a URL connection to the scheme and URL would return a stream, and the path in the URL exists as a directory on the server, the presence of the directory on the server could be inferred from the 404 response. The contents and other metadata about the directory are not exposed. This affects http4s versions: 0.21.7 through 0.21.23, 0.22.0-M1 through 0.22.0-M8, 0.23.0-M1, and 1.0.0-M1 through 1.0.0-M22. The [patch](https://github.com/http4s/http4s/commit/52e1890665410b4385e37b96bc49c5e3c708e4e9) is available in the following versions: v0.21.24, v0.22.0-M9, v0.23.0-M2, v1.0.0-M23. As a workaround users can avoid calling `StaticFile.fromUrl` with non-file URLs.

Affected packages & fixed versions

Affected products (as reported)

References

• https://github.com/http4s/http4s/security/advisories/GHSA-6h7w-fc84-x7p6 x_refsource_CONFIRM
• https://github.com/http4s/http4s/commit/52e1890665410b4385e37b96bc49c5e3c708e4e9 x_refsource_MISC
• https://mvnrepository.com/artifact/org.http4s/http4s-core x_refsource_MISC