cve/2021/CVE-2021-42390.md

### [CVE-2021-42390](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-42390)
![](https://img.shields.io/static/v1?label=Product&message=clickhouse&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=unspecified%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-369&color=brightgreen)

### Description

Divide-by-zero in Clickhouse's DeltaDouble 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.

### POC

#### Reference
- https://jfrog.com/blog/7-rce-and-dos-vulnerabilities-found-in-clickhouse-dbms

#### Github
No PoCs found on GitHub currently.