# CVE-2021-42697: Uncontrolled Recursion in Akka HTTP

Source: https://junglewise.ai/threats/cve-2021-42697-uncontrolled-recursion-in-akka-http  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-05-24  
License: CC BY 4.0 with a link back

CVE-2021-42697 · Severity: low · CVSS 3.1 · Published 2022-05-24

Uncontrolled Recursion in Akka HTTP

Technologies: [com.typesafe.akka:akka-http-core_2.11 (Maven)](https://junglewise.ai/threats/technologies/com-typesafe-akka-akka-http-core-2-11), [com.typesafe.akka:akka-http-core_2.12 (Maven)](https://junglewise.ai/threats/technologies/com-typesafe-akka-akka-http-core-2-12). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2021-42697 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-42697 being exploited in the wild.

**How severe is CVE-2021-42697?** Low severity, with a CVSS score of 3.1, published 24 May 2022.

**Which products and versions are affected?** com.typesafe.akka:aakka-http-core_2.13.0-M3 (Maven) ECOSYSTEM:introduced=10.1.0; com.typesafe.akka:akka-http-core_2.11 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15; com.typesafe.akka:akka-http-core_2.12 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15; com.typesafe.akka:akka-http-core_2.13 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15; and 3 more.

**Is there a fix for CVE-2021-42697?** Yes. com.typesafe.akka:akka-http-core_2.11 (Maven): upgrade to 10.1.15 or later; com.typesafe.akka:akka-http-core_2.12 (Maven): upgrade to 10.1.15 or later; com.typesafe.akka:akka-http-core_2.13 (Maven): upgrade to 10.1.15 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-42697?** Check whether you run com.typesafe.akka:aakka-http-core_2.13.0-M3 (Maven), com.typesafe.akka:akka-http-core_2.11 (Maven), com.typesafe.akka:akka-http-core_2.12 (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

- com.typesafe.akka:akka-http-core_2.11 (Maven): upgrade to 10.1.15 or later

  ```sh
  # set com.typesafe.akka:akka-http-core_2.11 to 10.1.15 in your pom.xml or build.gradle
  ```

- com.typesafe.akka:akka-http-core_2.12 (Maven): upgrade to 10.1.15 or later

  ```sh
  # set com.typesafe.akka:akka-http-core_2.12 to 10.1.15 in your pom.xml or build.gradle
  ```

- com.typesafe.akka:akka-http-core_2.13 (Maven): upgrade to 10.1.15 or later

  ```sh
  # set com.typesafe.akka:akka-http-core_2.13 to 10.1.15 in your pom.xml or build.gradle
  ```


## Affected products

- com.typesafe.akka:aakka-http-core_2.13.0-M3 (Maven) ECOSYSTEM:introduced=10.1.0
- com.typesafe.akka:akka-http-core_2.11 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15
- com.typesafe.akka:akka-http-core_2.12 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15
- com.typesafe.akka:akka-http-core_2.13 (Maven) ECOSYSTEM:introduced=10.1.0,fixed=10.1.15
- com.typesafe.akka:akka-http-core_2.13.0-M5 (Maven) ECOSYSTEM:introduced=10.1.0
- com.typesafe.akka:akka-http-core_2.13.0-RC2 (Maven) ECOSYSTEM:introduced=10.1.0
- com.typesafe.akka:akka-http-core_2.13.0-RC3 (Maven) ECOSYSTEM:introduced=10.1.0

## Identifiers

- CVE-2021-42697
- GHSA-3hw2-h67c-wq66

## Related threats

- [Multiple Vendors HTTP/2 denial of service via Rapid Reset attack](https://junglewise.ai/threats/cve-2023-44487-http-2-rapid-reset-attack-vulnerability)
- [Improper Restriction of Operations within the Bounds of a Memory Buffer in akka-http-core](https://junglewise.ai/threats/cve-2017-1000118-improper-restriction-of-operations-within-the-bounds-of-a)
- [High severity vulnerability that affects com.typesafe.akka:akka-http-core_2.11 and com.typesafe.akka:akka-http-core_2.12](https://junglewise.ai/threats/cve-2018-16131-high-severity-vulnerability-that-affects-com-typesafe-akka-akka)