CVE-2021-32643
StaticFile.fromUrl can leak presence of a directory
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 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
StaticFile.fromUrl can leak presence of a directory
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 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.
- Record
CVE-2021-32643- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2021-0971
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 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.
- Record
EUVD-2021-0971- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6h7w-fc84-x7p6
StaticFile.fromUrl can leak presence of a directory
Impact
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
- 1.0.0-M1 through 1.0.0-M22
Patches
The patch is available in the following versions:
- v0.21.24
- v0.22.0-RC1
- v0.23.0-RC1
- v1.0.0-M23
Note: a previous version of this advisory incorrectly referred to 0.22.0-M9 and 0.23.0-M2.
Workarounds
Don't call StaticFile.fromUrl with non-file URLs.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the http4s repository
- Disclose further vulnerabilities according to the http4s security policy
- Record
GHSA-6h7w-fc84-x7p6- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
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 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.
- Record
CVE-2021-32643- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
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 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.
- Record
CVE-2021-32643- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-6h7w-fc84-x7p6
StaticFile.fromUrl can leak presence of a directory
Impact
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
- 1.0.0-M1 through 1.0.0-M22
Patches
The patch is available in the following versions:
- v0.21.24
- v0.22.0-RC1
- v0.23.0-RC1
- v1.0.0-M23
Note: a previous version of this advisory incorrectly referred to 0.22.0-M9 and 0.23.0-M2.
Workarounds
Don't call StaticFile.fromUrl with non-file URLs.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the http4s repository
- Disclose further vulnerabilities according to the http4s security policy
- Record
GHSA-6h7w-fc84-x7p6- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.http4s:http4s-coreMaven |
0.21.7 up to 0.21.24 | 0.21.24 |
org.http4s:http4s-coreMaven |
0.22.0-M1 to 0.22.0-M8 | 0.22.0-RC1 |
org.http4s:http4s-coreMaven |
0.23.0-M1 to 0.23.0-M1 | 0.23.0-RC1 |
org.http4s:http4s-coreMaven |
1.0.0-M1 to 1.0.0-M22 | 1.0.0-M23 |
org.http4s:http4s-coreMaven |
0.22.0-M1 up to 0.22.0-RC1 | 0.22.0-RC1 |
org.http4s:http4s-coreMaven |
0.23.0-M1 up to 0.23.0-RC1 | 0.23.0-RC1 |
org.http4s:http4s-coreMaven |
1.0.0-M1 up to 1.0.0-M23 | 1.0.0-M23 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-32643 is a medium vulnerability (CVSS 5.8) in Http4s, published May 27, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.40%, the 72nd percentile. Fixed in org.http4s:http4s-core 0.21.24.