Vulnerability · Published Sep 4, 2020 · Assigned by facebook

CVE-2020-1911

Critical 9.8

In plain English

A critical-severity type confusion in Hermes from Facebook. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.0% (higher than 81% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)9.8Critical

Exploit odds (30 days)2.0%top 19.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

A type confusion vulnerability when resolving properties of JavaScript objects with specially-crafted prototype chains in Facebook Hermes prior to commit fe52854cdf6725c2eaa9e125995da76e6ceb27da allows attackers to potentially execute arbitrary code via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	hermes-engine	0.5.2	GHSA-f5x2-xv93-4p23

Affected products (as reported)

Vendor	Product	Versions
Facebook	Hermes	commit prior to fe52854cdf6725c2eaa9e125995da76e6ceb27da

Weakness: CWE-843

References

https://www.facebook.com/security/advisories/cve-2020-1911 x_refsource_CONFIRM
https://github.com/facebook/hermes/commit/fe52854cdf6725c2eaa9e125995da76e6ceb27da x_refsource_CONFIRM