CVE-2019-20398 Null dereference in n/a

Medium 6.5 Published 22 Jan 2020 Updated 5 Aug 2024

A NULL pointer dereference in libyang allows attackers to crash applications parsing untrusted YANG files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2019-20398?

CVE-2019-20398 is a medium-severity vulnerability in n/a, published on 22 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A NULL pointer dereference is present in libyang before v1.0-r3 in the function lys_extension_instances_free() due to a copy of unresolved extensions in lys_restr_dup(). Applications that use libyang to parse untrusted input yang files may crash.

Weakness: CWE-476

Which versions are affected by CVE-2019-20398?

It affects 1 product.

Products include Cesnet Libyang.

How do I fix CVE-2019-20398?

Upgrade to a fixed version.

Is CVE-2019-20398 being exploited?

There is no known exploitation of CVE-2019-20398 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2019-20398, GHSA-q259-qj8c-5r52, UBUNTU-CVE-2019-20398.