{
  "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-2023-27991",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2023-27991",
    "idYear": 2023,
    "status": "PUBLISHED",
    "publishedAt": "2023-04-24T00:00:00.000Z",
    "updatedAt": "2025-02-04T16:47:55.646Z",
    "importedAt": "2026-10-24T01:56:53.804Z",
    "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": null,
      "summary": "The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.",
      "affected": [
        {
          "vendor": "Zyxel",
          "product": "ATP series firmware",
          "versions": [
            {
              "version": "4.32 through 5.35",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Zyxel",
          "product": "USG FLEX series firmware",
          "versions": [
            {
              "version": "4.50 through 5.35",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Zyxel",
          "product": "USG FLEX 50(W) firmware",
          "versions": [
            {
              "version": "4.16 through 5.35",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Zyxel",
          "product": "USG20(W)-VPN firmware",
          "versions": [
            {
              "version": "4.16 through 5.35",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Zyxel",
          "product": "VPN series firmware",
          "versions": [
            {
              "version": "4.30 through 5.35",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}