CVE-2020-1914 Always-Incorrect Control Flow Implementation in Facebook Hermes
Attackers can read out-of-bounds memory or execute arbitrary code via crafted JavaScript in Hermes if untrusted script evaluation is permitted.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-1914?
CVE-2020-1914 is a critical memory corruption vulnerability in Facebook Hermes, published on 8 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-670
Which versions are affected by CVE-2020-1914?
2 open source packages ship an affected version, including hermes-engine. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
hermes-engine npm | All versions | 0.7.2 |
hermes-engine npm | All versions | 0.7.2 |
Products include Facebook Hermes.
How do I fix CVE-2020-1914?
Upgrade hermes-engine to 0.7.2 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2020-1914 being exploited?
There is no known exploitation of CVE-2020-1914 in the wild and no public exploit code.
Other vulnerabilities in Facebook Hermes
Sources
Also known as GHSA-327c-qx3v-h673.