Out-of-bounds Read in Clickhouse

CVE-2021-42387

Heap out-of-bounds read in Clickhouse's LZ4 compression codec when parsing a malicious query. As part of the LZ4::decompressImpl() loop, a 16-bit unsigned user-supplied value ('offset') is read from the compressed data. The offset is later used in the length of a copy operation, without checking the upper bounds of the source of the copy operation.

Vulnerability class: Buffer Overflow

EPSS: 0.015 (72.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-42387?
CVE-2021-42387 is a high-severity vulnerability in Clickhouse, classified under Out-of-bounds Read. CVSS score: 8.1/10. Published 2022-03-14.
How severe is CVE-2021-42387?
High severity. CVSS v3 base score is 8.1 out of 10.