Path Traversal in Http4s
CVE-2021-32643
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.014 (71.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 71.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000
Affected products
- Http4s — versions >= 0.21.7, < 0.21.24, >= 0.22.0-M1, <= 0.22.0-M8, = 0.23.0-M1
- Typelevel Http4s — versions 0.22.0, 0.23.0, 1.0.0
Weakness classification (CWE)
References
- github.com/http4s/http4s/security/advisories/GHSA-6h7w-fc84-x7p6 (Patch, Third Party Advisory)
- github.com/http4s/http4s/commit/52e1890665410b4385e37b96bc49c5e3c708e4e9 (Patch, Third Party Advisory)
- mvnrepository.com/artifact/org.http4s/http4s-core (Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32643?
- CVE-2021-32643 is a medium-severity vulnerability in Http4s, classified under Path Traversal. CVSS score: 5.8/10. Published 2021-05-27.
- How severe is CVE-2021-32643?
- Medium severity. CVSS v3 base score is 5.8 out of 10.