Is CVE-2021-24044 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2021-24044 being exploited in the wild.

How severe is CVE-2021-24044?

Low severity, with a CVSS score of 3.1, published 16 January 2022.

Which products and versions are affected?

hermes-engine (npm) SEMVER:introduced=0,fixed=0.10.0.

Is there a fix for CVE-2021-24044?

Yes. hermes-engine (npm): upgrade to 0.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2021-24044 attacked?

It is attacked over the network.

Am I affected by CVE-2021-24044?

Check whether you run hermes-engine (npm) 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.

CVE-2021-24044: Facebook Hermes type confusion via async/yield in getters/setters

CVE-2021-24044 · Severity: low · CVSS 3.1 · Published 2022-01-16

Hermes is a JavaScript engine used to power React Native applications. A type confusion vulnerability allows attackers to crash the engine or potentially execute arbitrary code by supplying specially crafted JavaScript code that misuses async and yield keywords in getter/setter functions, leading to memory safety violations.

Technologies: hermes-engine (npm). Vendors: npm.

Quick answers

Is CVE-2021-24044 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2021-24044 being exploited in the wild.
How severe is CVE-2021-24044?: Low severity, with a CVSS score of 3.1, published 16 January 2022.
Which products and versions are affected?: hermes-engine (npm) SEMVER:introduced=0,fixed=0.10.0.
Is there a fix for CVE-2021-24044?: Yes. hermes-engine (npm): upgrade to 0.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2021-24044 attacked?: It is attacked over the network.
Am I affected by CVE-2021-24044?: Check whether you run hermes-engine (npm) 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

hermes-engine (npm): upgrade to 0.10.0 or later
```
npm install hermes-engine@0.10.0
```

Technical details

This vulnerability is a type confusion (CWE-843) in Hermes' handling of async/generator syntax in non-async/non-generator getter and setter functions. When invalid JavaScript code attempts to use await or yield in these contexts, Hermes incorrectly invokes generator functions without proper type validation, resulting in a segmentation fault due to memory safety violations. The attack requires no authentication and is remotely exploitable via network-delivered JavaScript code (e.g., web views, RN applications). Attackers can achieve denial of service through crash, with a low but plausible probability of remote code execution. The vulnerability is resolved in Hermes v0.10.0 and later.

Affected products

Facebook Hermes prior to 0.10.0

Identifiers

CVE-2021-24044
GHSA-7mhc-prgv-r3q4

Timeline

2022-01-16: disclosed
2022-01-16: patched: Fixed in v0.10.0

References

https://github.com/facebook/hermes

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