CVE-2020-1913: facebook hermes Signed to Unsigned Conversion Error
Vulnerability summary
CVE-2020-1913 is a high (CVSS 8.1) Signed to Unsigned Conversion Error vulnerability in facebook hermes. EPSS estimates a 1.20% chance of exploitation in the next 30 days, higher than 67.8% of scored vulnerabilities.
Timeline
- 09-09-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
An Integer signedness error in the JavaScript Interpreter in Facebook Hermes prior to commit 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 allows attackers to cause a denial of service attack or a potential RCE 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.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · NpmEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
1.20%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
0.00 pp
From 1.20% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-195Signed to Unsigned Conversion ErrorThe product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.
- CWE-681Incorrect Conversion between Numeric TypesWhen converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.
Affected systems
Facebook1 product
- hermescommit prior to 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 | ≤ 0.4.3
Npm1 product
- hermes-engine< 0.5.2
2 vendors · 2 products
References
3 links- github.com/facebook/hermes/commit/2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6X Refsource CONFIRMWEBPatchThird Party Advisory
