CVE-2021-32643

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.

CvssV3 impact

BaseSeverity

MEDIUM

ConfidentialityImpact

LOW

AttackComplexity

LOW

Scope

CHANGED

AttackVector

NETWORK

AvailabilityImpact

NONE

IntegrityImpact

NONE

PrivilegesRequired

NONE

BaseScore

5.8

VectorString

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

LOW

ConfidentialityImpact

PARTIAL

AvailabilityImpact

NONE

IntegrityImpact

NONE

BaseScore

5

VectorString

AV:N/AC:L/Au:N/C:P/I:N/A:N

Version

2.0

AccessVector

NETWORK

Authentication

NONE