CVE-2021-42391 Denial of service in clickhouse

Medium 6.5 Published 14 Mar 2022 Updated 4 Aug 2024

A divide-by-zero error in ClickHouse's Gorilla compression codec allows attackers to cause a denial of service via a malicious query.

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

What is CVE-2021-42391?

CVE-2021-42391 is a medium-severity denial of service vulnerability in yandex clickhouse, published on 14 Mar 2022. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Divide-by-zero in Clickhouse's Gorilla compression codec when parsing a malicious query. The first byte of the compressed buffer is used in a modulo operation without being checked for 0.

Weakness: CWE-369

Which versions are affected by CVE-2021-42391?

It affects 1 product.

Products include Clickhouse Clickhouse.

How do I fix CVE-2021-42391?

No fix has been published for CVE-2021-42391 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-42391 being exploited?

There is no known exploitation of CVE-2021-42391 in the wild and no public exploit code.

Sources

Also known as GHSA-rfqp-qc69-jhvm.