CVE-2018-6345 Memory corruption in HHVM

Critical 9.8 Published 15 Jan 2019 Updated 5 Aug 2024

A heap overflow in HHVM's number_format function allows attackers to cause denial of service or potentially execute arbitrary code.

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-2018-6345?

CVE-2018-6345 is a critical memory corruption vulnerability in Facebook HHVM, published on 15 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The function number_format is vulnerable to a heap overflow issue when its second argument ($dec_points) is excessively large. The internal implementation of the function will cause a string to be created with an invalid length, which can then interact poorly with other functions. This affects all supported versions of HHVM (3.30.1 and 3.27.5 and below).

Weakness: CWE-787, CWE-122

Which versions are affected by CVE-2018-6345?

It affects 1 product.

Products include Facebook Hhvm.

How do I fix CVE-2018-6345?

No fix has been published for CVE-2018-6345 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2018-6345 being exploited?

There is no known exploitation of CVE-2018-6345 in the wild and no public exploit code.

Sources

Also known as GHSA-g4fr-ffvg-p5w6, UBUNTU-CVE-2018-6345.