CVE-2021-41084

HIGH

http4s < 0.21.29 - HTTP Response Splitting via Header and URI Field Injection

Title source: llm
STIX 2.1

Description

http4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when untrusted user input is used to create any of the following fields: Header names (`Header.name`å), Header values (`Header.value`), Status reason phrases (`Status.reason`), URI paths (`Uri.Path`), URI authority registered names (`URI.RegName`) (through 0.21). This issue has been resolved in versions 0.21.30, 0.22.5, 0.23.4, and 1.0.0-M27 perform the following. As a matter of practice http4s services and client applications should sanitize any user input in the aforementioned fields before returning a request or response to the backend. The carriage return, newline, and null characters are the most threatening.

References (4)

Core 4

Scores

CVSS v3 8.7
EPSS 0.0120
EPSS Percentile 64.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Details

CWE
CWE-74 CWE-918
Status published
Products (11)
org.http4s/http4s-client_2.12 0 - 0.21.29Maven
org.http4s/http4s-client_2.13 0 - 0.21.29Maven
org.http4s/http4s-client_3 0 - 0.21.29Maven
org.http4s/http4s-server_2.10 0Maven
org.http4s/http4s-server_2.11 0Maven
org.http4s/http4s-server_2.12 0 - 0.21.29Maven
org.http4s/http4s-server_2.13 0 - 0.21.29Maven
org.http4s/http4s-server_2.13.0-M5 0Maven
org.http4s/http4s-server_3 0.22.0 - 0.22.5Maven
typelevel/http4s 1.0.0 milestone1 (26 CPE variants)
... and 1 more
Published Sep 21, 2021
Tracked Since Feb 18, 2026