SSRF in Http4s
CVE-2021-41084
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.012 (66.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N.
Affected products
- Http4s — versions <= 0.21.28, >= 0.22.0, < 0.22.5, >= 0.23.0, < 0.23.4
- Typelevel Http4s — versions 1.0.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Vendor Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-41084?
- CVE-2021-41084 is a high-severity vulnerability in Http4s, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.7/10. Published 2021-09-21.
- How severe is CVE-2021-41084?
- High severity. CVSS v3 base score is 8.7 out of 10.