Quick answers
- Is CVE-2020-1911 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2020-1911 being exploited in the wild.
- How severe is CVE-2020-1911?
- Low severity, with a CVSS score of 3.1, published 24 May 2022.
- Which products and versions are affected?
- hermes-engine (npm) SEMVER:introduced=0,fixed=0.5.2.
- Is there a fix for CVE-2020-1911?
- Yes. hermes-engine (npm): upgrade to 0.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2020-1911 attacked?
- It is attacked over the network.
- Am I affected by CVE-2020-1911?
- 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 0.5.2 or later
npm install hermes-engine@0.5.2
Technical details
This is a type confusion vulnerability (CWE-843) in Facebook Hermes' property resolution logic when handling JavaScript objects with specially-crafted prototype chains. The root cause is improper handling of HostObject computed properties during prototype chain lookups in the JSObject component. An attacker who can provide crafted JavaScript code to the Hermes engine can trigger arbitrary code execution. The vulnerability requires the application to permit evaluation of untrusted JavaScript—most React Native applications do not enable this capability and are therefore not affected. The fix was committed in Hermes prior to version 0.5.2; versions 0.4.3 and earlier are vulnerable.
Affected products
- Facebook Hermes prior to 0.5.2
Identifiers
- CVE-2020-1911
- GHSA-f5x2-xv93-4p23
Timeline
- 2020-09-04: disclosed: Published on NVD
- 2022-05-24: advisory: GitHub advisory GHSA-f5x2-xv93-4p23 published
- 2020: patched: Fixed in Hermes 0.5.2