{
  "cveId": "CVE-2021-42387",
  "url": "https://patchblox.com/security/cve/CVE-2021-42387",
  "summary": "CVE-2021-42387 is fixed in 5 products on 1 platform, first by clickhouse-client 18.16.1\u002Bds-7ubuntu0.1, released March 14, 2022. It is not reported as exploited. Patch Radar priority: High.",
  "title": "clickhouse: Heap out-of-bounds read in Clickhouse\u0027s LZ4 compression codec when parsing a malicious query",
  "description": "Heap out-of-bounds read in Clickhouse\u0027s LZ4 compression codec when parsing a malicious query. As part of the LZ4::decompressImpl() loop, a 16-bit unsigned user-supplied value (\u0027offset\u0027) 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.",
  "published": "2022-03-14T16:15:00Z",
  "severity": "high",
  "cvss": 8.1,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
  "epss": 0.01573,
  "epssPercentile": 0.75564,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "clickhouse",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "18.16.1\u002Bds-7.3",
      "fix": "DEBIAN-CVE-2021-42387",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-42387",
      "released": "2022-03-14T23:15:07Z"
    },
    {
      "platform": "linux",
      "product": "clickhouse-client",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "18.16.1\u002Bds-7ubuntu0.1",
      "fix": "clickhouse-client 18.16.1\u002Bds-7ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-clickhouse-client-18.16.1-ds-7ubuntu0.1",
      "released": "2022-03-14T16:15:00Z"
    },
    {
      "platform": "linux",
      "product": "clickhouse-common",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "18.16.1\u002Bds-7ubuntu0.1",
      "fix": "clickhouse-common 18.16.1\u002Bds-7ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-clickhouse-common-18.16.1-ds-7ubuntu0.1",
      "released": "2022-03-14T16:15:00Z"
    },
    {
      "platform": "linux",
      "product": "clickhouse-server",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "18.16.1\u002Bds-7ubuntu0.1",
      "fix": "clickhouse-server 18.16.1\u002Bds-7ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-clickhouse-server-18.16.1-ds-7ubuntu0.1",
      "released": "2022-03-14T16:15:00Z"
    },
    {
      "platform": "linux",
      "product": "clickhouse-tools",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "18.16.1\u002Bds-7ubuntu0.1",
      "fix": "clickhouse-tools 18.16.1\u002Bds-7ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-clickhouse-tools-18.16.1-ds-7ubuntu0.1",
      "released": "2022-03-14T16:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}