CVE-2021-41084
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…
Does this matter?
Lower severity and a low EPSS score (1.23%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
- EPSS
- 1.23% probability · 67th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918, CWE-74
- Affected
- typelevel/http4s
- Source
- security-advisories@github.com
References
- https://github.com/http4s/http4s/commit/d02007db1da4f8f3df2dbf11f1db9ac7afc3f9d8Patch, Third Party Advisory
- https://github.com/http4s/http4s/security/advisories/GHSA-5vcm-3xc3-w7x3Exploit, Third Party Advisory
- https://httpwg.org/http-core/draft-ietf-httpbis-semantics-latest.html#fields.valuesVendor Advisory
- https://owasp.org/www-community/attacks/HTTP_Response_SplittingThird Party Advisory
- https://github.com/http4s/http4s/commit/d02007db1da4f8f3df2dbf11f1db9ac7afc3f9d8Patch, Third Party Advisory
- https://github.com/http4s/http4s/security/advisories/GHSA-5vcm-3xc3-w7x3Exploit, Third Party Advisory
- https://httpwg.org/http-core/draft-ietf-httpbis-semantics-latest.html#fields.valuesVendor Advisory
- https://owasp.org/www-community/attacks/HTTP_Response_SplittingThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.