# CVE-2021-41084: Response Splitting from unsanitized headers

Source: https://junglewise.ai/threats/cve-2021-41084-response-splitting-from-unsanitized-headers  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-09-22  
License: CC BY 4.0 with a link back

CVE-2021-41084 · Severity: low · CVSS 3.1 · Published 2021-09-22

Response Splitting from unsanitized headers

Technologies: [org.http4s:http4s-client_2.12 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-client-2-12), [org.http4s:http4s-client_2.13 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-client-2-13), [org.http4s:http4s-client_3 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-client-3), [org.http4s:http4s-server_2.12 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-server-2-12), [org.http4s:http4s-server_2.13 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-server-2-13), [org.http4s:http4s-server_3 (Maven)](https://junglewise.ai/threats/technologies/org-http4s-http4s-server-3). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2021-41084 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-41084 being exploited in the wild.

**How severe is CVE-2021-41084?** Low severity, with a CVSS score of 3.1, published 22 September 2021.

**Which products and versions are affected?** org.http4s:http4s-client_2.12 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29; org.http4s:http4s-client_2.13 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29; org.http4s:http4s-client_3 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29; org.http4s:http4s-server_2.10 (Maven) ECOSYSTEM:introduced=0,last_affected=0.21.28; and 5 more.

**Is there a fix for CVE-2021-41084?** Yes. org.http4s:http4s-client_2.12 (Maven): upgrade to 0.21.29 or later; org.http4s:http4s-client_2.13 (Maven): upgrade to 0.21.29 or later; org.http4s:http4s-client_3 (Maven): upgrade to 0.21.29 or later; org.http4s:http4s-server_2.12 (Maven): upgrade to 0.21.29 or later; org.http4s:http4s-server_2.13 (Maven): upgrade to 0.21.29 or later; org.http4s:http4s-server_3 (Maven): upgrade to 0.22.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-41084?** Check whether you run org.http4s:http4s-client_2.12 (Maven), org.http4s:http4s-client_2.13 (Maven), org.http4s:http4s-client_3 (Maven) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.http4s:http4s-client_2.12 (Maven): upgrade to 0.21.29 or later

  ```sh
  # set org.http4s:http4s-client_2.12 to 0.21.29 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-client_2.13 (Maven): upgrade to 0.21.29 or later

  ```sh
  # set org.http4s:http4s-client_2.13 to 0.21.29 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-client_3 (Maven): upgrade to 0.21.29 or later

  ```sh
  # set org.http4s:http4s-client_3 to 0.21.29 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-server_2.12 (Maven): upgrade to 0.21.29 or later

  ```sh
  # set org.http4s:http4s-server_2.12 to 0.21.29 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-server_2.13 (Maven): upgrade to 0.21.29 or later

  ```sh
  # set org.http4s:http4s-server_2.13 to 0.21.29 in your pom.xml or build.gradle
  ```

- org.http4s:http4s-server_3 (Maven): upgrade to 0.22.5 or later

  ```sh
  # set org.http4s:http4s-server_3 to 0.22.5 in your pom.xml or build.gradle
  ```


## Affected products

- org.http4s:http4s-client_2.12 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29
- org.http4s:http4s-client_2.13 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29
- org.http4s:http4s-client_3 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29
- org.http4s:http4s-server_2.10 (Maven) ECOSYSTEM:introduced=0,last_affected=0.21.28
- org.http4s:http4s-server_2.11 (Maven) ECOSYSTEM:introduced=0,last_affected=0.21.28
- org.http4s:http4s-server_2.12 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29
- org.http4s:http4s-server_2.13 (Maven) ECOSYSTEM:introduced=0,fixed=0.21.29
- org.http4s:http4s-server_2.13.0-M5 (Maven) ECOSYSTEM:introduced=0,last_affected=0.21.28
- org.http4s:http4s-server_3 (Maven) ECOSYSTEM:introduced=0.22.0,fixed=0.22.5

## Identifiers

- CVE-2021-41084
- GHSA-5vcm-3xc3-w7x3

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