{
  "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-2021-47245",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47245",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-21T14:19:43.648Z",
    "updatedAt": "2026-08-05T08:46:56.392Z",
    "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": "netfilter: synproxy: Fix out of bounds when parsing TCP options",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: synproxy: Fix out of bounds when parsing TCP options\n\nThe TCP option parser in synproxy (synproxy_parse_options) could read\none byte out of bounds. When the length is 1, the execution flow gets\ninto the loop, reads one byte of the opcode, and if the opcode is\nneither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds\nthe 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 an early return when length < 0 to avoid calling\nskb_header_pointer with negative length.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "576c1526b4d83c44ad7b673cb841f36cbc6cb6c4"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "674b5f0c6a4fc5d3abce877048290cea6091fcb1"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7d9a9a1a88a3da574e019b4de756bc73337b3b0b"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6defc77d48eff74075b80ad5925061b2fc010d98"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9cdf299ba4e153b5e56187648420de22c6216f02"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f648089337cb8ed40b2bb96e244f72b9d97dc96b"
            },
            {
              "version": "48b1de4c110a7afa4b85862f6c75af817db26fad",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5fc177ab759418c9537433e63301096e733fb915"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "3.12",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "3.12"
            },
            {
              "version": "4.4.274",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.4.*"
            },
            {
              "version": "4.9.274",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.9.*"
            },
            {
              "version": "4.14.238",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.14.*"
            },
            {
              "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": "*"
            }
          ]
        }
      ]
    }
  }
}