CVE-2023-24833 Use after free in Hermes

High 7.5 Published 18 May 2023 Updated 21 Jan 2025

An attacker can leak raw heap data via a use-after-free in Hermes when executing untrusted JavaScript, primarily affecting React Native apps with such configurations.

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-2023-24833?

CVE-2023-24833 is a high-severity 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 in BigIntPrimitive addition in Hermes prior to commit a6dcafe6ded8e61658b40f5699878cd19a481f80 could have been used by an attacker to leak raw data from Hermes VM’s heap. 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-2023-24833?

It affects 1 product.

Products include Facebook Hermes.

How do I fix CVE-2023-24833?

No fix has been published for CVE-2023-24833 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-2023-24833 being exploited?

There is no known exploitation of CVE-2023-24833 in the wild and no public exploit code.

Sources

Also known as GHSA-c3mx-jjr9-q7cc.