CVE catalog
CVE-2021-42387
clickhouse: CVE-2021-42387
- Severity
- Medium
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 1.57% · Oct 25, 2026
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 upper bounds of the source of the copy operation.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | clickhouse | bookworm | 18.16.1+ds-7.3 | fixed |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5ubuntu1 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5ubuntu2 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-6ubuntu1 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-7 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-7ubuntu0.1 | fixed |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5ubuntu1 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-5ubuntu2 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-6ubuntu1 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-7 | vulnerable |
| Ubuntu | clickhouse | 20.04 | 18.16.1+ds-7ubuntu0.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | clickhouse | source | bookworm | 18.16.1+ds-7.3 | not yet assigned | Not reported | [1008216] |
| Ubuntu | clickhouse | deb | 20.04 | 18.16.1+ds-7ubuntu0.1 | Not reported | USN-6933-1 | Not reported |
| Ubuntu | clickhouse | deb | 20.04 | 18.16.1+ds-7ubuntu0.1 | Not reported | UBUNTU-CVE-2021-42387 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [clickhouse-client]Fixed
Source package: [clickhouse]
Details (2)
18.16.1+ds-7.3+b2· amd64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
18.16.1+ds-7.3+b2· arm64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
- [clickhouse-common]Fixed
Source package: [clickhouse]
Details (2)
18.16.1+ds-7.3+b2· amd64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
18.16.1+ds-7.3+b2· arm64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
- [clickhouse-server]Fixed
Source package: [clickhouse]
Details (2)
18.16.1+ds-7.3+b2· amd64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
18.16.1+ds-7.3+b2· arm64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
- [clickhouse-tools]Fixed
Source package: [clickhouse]
Details (2)
18.16.1+ds-7.3+b2· amd64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
18.16.1+ds-7.3+b2· arm64 · bookwormFixed · Fixed:
18.16.1+ds-7.3dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12
Observed:
References
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-42387]
- [https://osv.dev/vulnerability/DLA-3176-1]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-42387]
- [https://osv.dev/vulnerability/USN-6933-1]
- [https://security-tracker.debian.org/tracker/CVE-2021-42387]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]