What’s Vulnerable › Vulnerabilities
CVE-2021-42388
- Severity: high (CVSS 8.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.6% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2022-03-14 · updated 2026-06-17
- Weakness: CWE-125
Description
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 lower bounds of the source of the copy operation.
Affected products
- ClickHouse: before 21.10.2.15 — fixed in 21.10.2.15
- Debian Linux: 10.0
How to fix
Upgrade to a fixed version: ClickHouse 21.10.2.15. Check the vendor advisory for mitigations.
References
- https://jfrog.com/blog/7-rce-and-dos-vulnerabilities-found-in-clickhouse-dbms
- https://lists.debian.org/debian-lts-announce/2022/11/msg00002.html
- https://jfrog.com/blog/7-rce-and-dos-vulnerabilities-found-in-clickhouse-dbms
- https://lists.debian.org/debian-lts-announce/2022/11/msg00002.html
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