Vulnerability · Published Oct 8, 2020 · Assigned by facebook

CVE-2020-1914

Critical 9.8

In plain English

A critical-severity security flaw 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 2.5% (higher than 85% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)9.8Critical

Exploit odds (30 days)2.5%top 15.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

A logic vulnerability when handling the SaveGeneratorLong instruction in Facebook Hermes prior to commit b2021df620824627f5a8c96615edbd1eb7fdddfc allows attackers to potentially read out of bounds or theoretically 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	0.7.2	GHSA-327c-qx3v-h673

Affected products (as reported)

Vendor	Product	Versions
Facebook	Hermes	commit prior to b2021df620824627f5a8c96615edbd1eb7fdddfc

Weakness: CWE-670

References

https://www.facebook.com/security/advisories/cve-2020-1914 x_refsource_CONFIRM
https://github.com/facebook/hermes/commit/b2021df620824627f5a8c96615edbd1eb7fdddfc x_refsource_CONFIRM