CVE-2021-43305
HIGHEPSS 74th pctlDescription
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.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Elevated risk: more likely to be exploited than 74% of all known CVEs.
References
Related Vulnerabilities
Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2015-3113 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2024-26256 | High | 7.8 | 88% | - | Fix |
| CVE-2020-25687 | Medium | 5.9 | 87% | - | Fix |
| CVE-2009-3459 | High | 8.8 | 86% | KEV | Fix |
| CVE-2021-21017 | High | 8.8 | 86% | KEV | - |
| CVE-2020-25683 | Medium | 5.9 | 86% | - | Fix |
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Markdown
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-06-25.