{
  "cveId": "CVE-2020-0688",
  "url": "https://patchblox.com/security/cve/CVE-2020-0688",
  "summary": "CVE-2020-0688 is fixed in 6 products on 1 platform, first by KB4536989, released February 11, 2020. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, with known ransomware use. Patch Radar priority: Patch now.",
  "title": "Microsoft Exchange Validation Key Remote Code Execution Vulnerability",
  "description": "\u003Cp\u003EA remote code execution vulnerability exists in Microsoft Exchange Server when the server fails to properly create unique keys at install time.\u003C/p\u003E\n\u003Cp\u003EKnowledge of a the validation key allows an authenticated user with a mailbox to pass arbitrary objects to be deserialized by the web application, which runs as SYSTEM.\u003C/p\u003E\n\u003Cp\u003EThe security update addresses the vulnerability by correcting how Microsoft Exchange creates the keys during install.\u003C/p\u003E",
  "published": "2020-02-11T14:00:00Z",
  "severity": "Important",
  "epss": 0.99955,
  "epssPercentile": 0.99974,
  "priority": "Patch now",
  "priorityTier": 1,
  "exploited": true,
  "vendorExploited": false,
  "disclosed": false,
  "exploitabilityAssessment": "Exploitation More Likely",
  "kev": {
    "added": "2021-11-03T00:00:00Z",
    "due": "2022-05-03T00:00:00Z",
    "ransomware": true,
    "requiredAction": "Apply updates per vendor instructions."
  },
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-0688",
  "fixes": [
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 30",
      "fixedVersion": "",
      "fix": "KB4536989",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536989",
      "released": "2020-02-11T14:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2013 Cumulative Update 23",
      "fixedVersion": "",
      "fix": "KB4536988",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536988",
      "released": "2020-02-11T14:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2016 Cumulative Update 14",
      "fixedVersion": "",
      "fix": "KB4536987",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536987",
      "released": "2020-02-11T14:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2016 Cumulative Update 15",
      "fixedVersion": "",
      "fix": "KB4536987",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536987",
      "released": "2020-02-11T14:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2019 Cumulative Update 3",
      "fixedVersion": "",
      "fix": "KB4536987",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536987",
      "released": "2020-02-11T14:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft Exchange Server 2019 Cumulative Update 4",
      "fixedVersion": "",
      "fix": "KB4536987",
      "url": "https://patchblox.com/security/fix/microsoft/kb4536987",
      "released": "2020-02-11T14:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}