CVE-2021-43304
Heap buffer overflow in Clickhouse's LZ4 compression codec when parsing a malicious query. There...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-43304- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-43304- Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2021-30247 No score
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.
- Record
EUVD-2021-30247- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4px5-4p3v-7568
Heap buffer overflow in Clickhouse's LZ4 compression codec when parsing a malicious query. There...
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.
- Record
GHSA-4px5-4p3v-7568- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122, CWE-787
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-43304- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-43304
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.
- Record
DEBIAN-CVE-2021-43304- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
clickhouseDebian:12 |
before 18.16.1+ds-7.3 | 18.16.1+ds-7.3 |
clickhouseDebian:10 From an advisory covering 4 CVEs |
before 18.16.1+ds-4+deb10u1, plus listed versions 18.16.1+ds-4 |
18.16.1+ds-4+deb10u1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43304 is a high vulnerability (CVSS 8.8) in Clickhouse, published March 14, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.67%, the 76th percentile. Fixed in clickhouse 18.16.1+ds-7.3.