CVE catalog

CVE-2021-42388

clickhouse affected and fixed versions

[CVE catalog]

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 lower bounds of the source of the copy operation.

Severity
Medium
Published
Source
[NVD] · [CVE record]
EPSS
1.57% · Oct 27, 2026

Projects and upstream resources

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Distribution / releasePackageVersionStatusSource
Debianbookwormclickhouse18.16.1+ds-7.3FixedDistribution-reported fixed boundary[CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-7ubuntu0.1Fixed[UBUNTU-CVE-2021-42388]

Showing 2 fix observations. All 7 observations, including unknown and conflicting reports, are available below.

Provider details and historical evidence
Distribution / releasePackageVersionStatusSource
Debianbookwormclickhouse18.16.1+ds-7.3FixedDistribution-reported fixed boundary[CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-5Affected[UBUNTU-CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-5ubuntu1Affected[UBUNTU-CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-5ubuntu2Affected[UBUNTU-CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-6ubuntu1Affected[UBUNTU-CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-7Affected[UBUNTU-CVE-2021-42388]
Ubuntu20.04clickhouse18.16.1+ds-7ubuntu0.1Fixed[UBUNTU-CVE-2021-42388]
Original provider fields
{
  "package_releases": [
    {
      "name": "clickhouse",
      "status": "fixed",
      "release": "bookworm",
      "version": "18.16.1+ds-7.3"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1008216,
      "name": "clickhouse",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": "18.16.1+ds-7.3"
    }
  ],
  "distribution_packages": [
    {
      "name": "clickhouse",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "18.16.1+ds-7ubuntu0.1"
            }
          ]
        }
      ],
      "release": "20.04",
      "versions": [
        "18.16.1+ds-5",
        "18.16.1+ds-5ubuntu1",
        "18.16.1+ds-5ubuntu2",
        "18.16.1+ds-6ubuntu1",
        "18.16.1+ds-7"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-42388",
      "fixed_version": "18.16.1+ds-7ubuntu0.1",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-42388",
      "provider_updated_at": "2026-02-04T04:37:24.314625Z"
    }
  ]
}

[Debian bug #1008216]

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

  • [clickhouse-client]Unknown

    Source package: [clickhouse]

    Details (2)

    • 18.16.1+ds-7.3+b2 · amd64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

    • 18.16.1+ds-7.3+b2 · arm64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

  • [clickhouse-common]Unknown

    Source package: [clickhouse]

    Details (2)

    • 18.16.1+ds-7.3+b2 · amd64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

    • 18.16.1+ds-7.3+b2 · arm64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

  • [clickhouse-server]Unknown

    Source package: [clickhouse]

    Details (2)

    • 18.16.1+ds-7.3+b2 · amd64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

    • 18.16.1+ds-7.3+b2 · arm64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

  • [clickhouse-tools]Unknown

    Source package: [clickhouse]

    Details (2)

    • 18.16.1+ds-7.3+b2 · amd64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

    • 18.16.1+ds-7.3+b2 · arm64 · bookworm

      Fixed · Fixed: 18.16.1+ds-7.3

      dsa · clickhouse · debian · bookworm; dsa · clickhouse · debian · 12

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]