Vulnerability in Http4s

CVE-2021-39185

Http4s is a minimal, idiomatic Scala interface for HTTP services. In http4s versions 0.21.26 and prior, 0.22.0 through 0.22.2, 0.23.0, 0.23.1, and 1.0.0-M1 through 1.0.0-M24, the default CORS configuration is vulnerable to an origin reflection attack. The middleware is also susceptible to a Null Origin Attack. The problem is fixed in 0.21.27, 0.22.3, 0.23.2, and 1.0.0-M25. The original `CORS` implementation and `CORSConfig` are deprecated. See the GitHub GHSA for more information, including code examples and workarounds.

EPSS: 0.006 (44.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

  • Http4s — versions < 0.21.27, >= 0.22.0, < 0.22.3, >= 0.23.0, < 0.23.2
  • Typelevel Http4s — versions 0.23.0, 0.23.1, 1.0.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-39185?
CVE-2021-39185 is a critical-severity vulnerability in Http4s, classified under Origin Validation Error. CVSS score: 9.1/10. Published 2021-09-01.
How severe is CVE-2021-39185?
Critical severity. CVSS v3 base score is 9.1 out of 10.