CVE-2023-30470 Use after free in Hermes

Critical 9.8 Published 18 May 2023 Updated 21 Jan 2025

An attacker can achieve remote code execution via a use-after-free in Hermes when executing untrusted JavaScript with optimizations enabled.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2023-30470?

CVE-2023-30470 is a critical use after free vulnerability in Facebook Hermes, published on 18 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A use-after-free related to unsound inference in the bytecode generation when optimizations are enabled for Hermes prior to commit da8990f737ebb9d9810633502f65ed462b819c09 could have been used by an attacker to achieve remote code execution. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.

Weakness: CWE-416

Which versions are affected by CVE-2023-30470?

It affects 1 product.

Products include Facebook Hermes.

How do I fix CVE-2023-30470?

No fix has been published for CVE-2023-30470 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2023-30470 being exploited?

There is no known exploitation of CVE-2023-30470 in the wild and no public exploit code.

Sources

Also known as GHSA-prjh-7gr6-423r.