CVE-2020-1911 Access of Resource Using Incompatible Type in Facebook Hermes
Type confusion in Hermes allows arbitrary code execution if the application evaluates untrusted JavaScript.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-1911?
CVE-2020-1911 is a critical memory corruption vulnerability in Facebook Hermes, published on 4 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-843
Which versions are affected by CVE-2020-1911?
2 open source packages ship an affected version, including hermes-engine. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
hermes-engine npm | All versions | 0.5.2 |
hermes-engine npm | All versions | 0.5.2 |
Products include Facebook Hermes.
How do I fix CVE-2020-1911?
Upgrade hermes-engine to 0.5.2 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2020-1911 being exploited?
There is no known exploitation of CVE-2020-1911 in the wild and no public exploit code.
Other vulnerabilities in Facebook Hermes
Sources
Also known as GHSA-f5x2-xv93-4p23.