Every CVE Search/ Get API key

CVE-2021-43305

Heap buffer overflow in Clickhouse's LZ4 compression codec when parsing a malicious query. There...

8.8 HighFix available

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.

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

1.67%Up 0.8 points since Mar 15, 2022
90%50%10%1%

What each source reports

NVD Score used 8.8

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.

Record
CVE-2021-43305
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0
6.5 MediumAV: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. This issue is very similar to CVE-2021-43304, but the vulnerable copy operation is in a different wildCopy call.

Record
CVE-2021-43305
Weakness
CWE-122
Updated
2026-11-02
EUVDEUVD-2021-30248 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. This issue is very similar to CVE-2021-43304, but the vulnerable copy operation is in a different wildCopy call.

Record
EUVD-2021-30248
Updated
2026-11-03
GitHub AdvisoriesGHSA-rjm8-hjq2-73j6 8.8

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. This issue is very similar to CVE-2021-43304, but the vulnerable copy operation is in a different wildCopy call.

Record
GHSA-rjm8-hjq2-73j6
CVSS 3.1
8.8 HighCVSS: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 8.8

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.

Record
CVE-2021-43305
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVDEBIAN-CVE-2021-43305 8.8

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.

Record
DEBIAN-CVE-2021-43305
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVUBUNTU-CVE-2021-43305 8.8

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.

Record
UBUNTU-CVE-2021-43305
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVUSN-6933-1 No score

clickhouse vulnerabilities

It was discovered that ClickHouse incorrectly handled memory, leading to a heap out-of-bounds data read. An attacker could possibly use this issue to cause a denial of service, or leak sensitive information. (CVE-2021-42387, CVE-2021-41388)

It was discovered that ClickHouse incorrectly handled memory, leading to a heap-based buffer overflow. An attacker could possibly use this issue to cause a denial of service, or execute arbitrary code. (CVE-2021-43305)

Record
USN-6933-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
clickhouse
Debian:12
before 18.16.1+ds-7.3
18.16.1+ds-7.3
clickhouse
Debian:10
before 18.16.1+ds-4+deb10u1, plus listed versions
18.16.1+ds-4
18.16.1+ds-4+deb10u1
clickhouse
Ubuntu:20.04:LTS
before 18.16.1+ds-7ubuntu0.1, plus listed versions
18.16.1+ds-518.16.1+ds-5ubuntu118.16.1+ds-5ubuntu218.16.1+ds-6ubuntu118.16.1+ds-7
18.16.1+ds-7ubuntu0.1

History

History
RecordedChangedSources
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-43305 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.

References

Show 7 moreShow less
MoveEnter Open