{
  "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-2020-12494",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2020-12494",
    "idYear": 2020,
    "status": "PUBLISHED",
    "publishedAt": "2020-06-16T13:28:38.000Z",
    "updatedAt": "2024-08-04T11:56:52.090Z",
    "importedAt": "2026-10-24T01:56:12.831Z",
    "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": "Beckhoff: Etherleak in TwinCAT RT network driver",
      "summary": "Beckhoff's TwinCAT RT network driver for Intel 8254x and 8255x is providing EtherCAT functionality. The driver implements real-time features. Except for Ethernet frames sent from real-time functionality, all other Ethernet frames sent through the driver are not padded if their payload is less than the minimum Ethernet frame size. Instead, arbitrary memory content is transmitted within in the padding bytes of the frame. Most likely this memory contains slices from previously transmitted or received frames. By this method, memory content is disclosed, however, an attacker can hardly control which memory content is affected. For example, the disclosure can be provoked with small sized ICMP echo requests sent to the device.",
      "affected": [
        {
          "vendor": "Beckhoff",
          "product": "TwinCat Driver for Intel 8254x (Tcl8254x.sys)",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "3.1.0.3603 for TwinCAT 3.1 4024"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "3.1.0.3512 for TwinCAT 3.1 4022"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "2.11.0.2120 for TwinCAT 2.11 2350"
            }
          ]
        },
        {
          "vendor": "Beckhoff",
          "product": "TwinCat Driver for Intel 8255x (Tcl8255x.sys)",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "3.1.0.3600 for TwinCAT 3.1 4024"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "3.1.0.3500 for TwinCAT 3.1 4024"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThanOrEqual": "2.11.0.2117 for TwinCAT 2.11 2350"
            }
          ]
        }
      ]
    }
  }
}