{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-47243",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47243",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-21T14:19:42.309Z",
    "updatedAt": "2026-08-05T08:46:54.221Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "sch_cake: Fix out of bounds when parsing TCP options and header",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_cake: Fix out of bounds when parsing TCP options and header\n\nThe TCP option parser in cake qdisc (cake_get_tcpopt and\ncake_tcph_may_drop) could read one byte out of bounds. When the length\nis 1, the execution flow gets into the loop, reads one byte of the\nopcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads\none more byte, which exceeds the length of 1.\n\nThis fix is inspired by commit 9609dad263f8 (\"ipv4: tcp_input: fix stack\nout of bounds when parsing TCP options.\").\n\nv2 changes:\n\nAdded doff validation in cake_get_tcphdr to avoid parsing garbage as TCP\nheader. Although it wasn't strictly an out-of-bounds access (memory was\nallocated), garbage values could be read where CAKE expected the TCP\nheader if doff was smaller than 5.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "8b7138814f29933898ecd31dfc83e35a30ee69f5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "595897ef118d6fe66690c4fc5b572028c9da95b7"
            },
            {
              "version": "8b7138814f29933898ecd31dfc83e35a30ee69f5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4cefa061fc63f4d2dff5ab4083f43857cd7a2335"
            },
            {
              "version": "8b7138814f29933898ecd31dfc83e35a30ee69f5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3b491dd593d582ceeb27aa617600712a6bd14246"
            },
            {
              "version": "8b7138814f29933898ecd31dfc83e35a30ee69f5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3371392c60e2685af30bd4547badd880f5df2b3f"
            },
            {
              "version": "8b7138814f29933898ecd31dfc83e35a30ee69f5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ba91c49dedbde758ba0b72f57ac90b06ddf8e548"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.19",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.19"
            },
            {
              "version": "4.19.196",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.128",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.46",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.12.13",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.12.*"
            },
            {
              "version": "5.13",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}