What’s Vulnerable › Vulnerabilities
CVE-2021-43305
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.7% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2022-03-14 · updated 2026-06-17
- Weakness: CWE-122
Description
Heap buffer overflow in Clickhouse's LZ4 compression codec when parsing a malicious query. There is no verification that the copy operations in the LZ4::decompressImpl loop and especially the arbitrary copy operation wildCopy<copy_amount>(op, ip, copy_end), don’t exceed the destination buffer’s limits. This issue is very similar to CVE-2021-43304, but the vulnerable copy operation is in a different wildCopy call.
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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