{
  "cveId": "CVE-2021-38501",
  "url": "https://patchblox.com/security/cve/CVE-2021-38501",
  "summary": "CVE-2021-38501 is fixed in 11 products on 2 platforms, first by Mozilla Thunderbird (en-US) 91.2.0, released October 4, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "Mozilla Firefox ESR and 3 others: Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1.",
  "description": "Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox \u003C 93, Thunderbird \u003C 91.2, and Firefox ESR \u003C 91.2.",
  "published": "2021-10-11T00:00:00Z",
  "severity": "Important",
  "cvss": 8.8,
  "epss": 0.01048,
  "epssPercentile": 0.64433,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://nvd.nist.gov/vuln/detail/CVE-2021-38501",
  "fixes": [
    {
      "platform": "windows-app",
      "product": "Mozilla Firefox ESR (en-US)",
      "fixedVersion": "102.0",
      "fix": "Mozilla Firefox ESR (en-US) 102.0",
      "url": "https://patchblox.com/security/fix/windows-app/mozilla.firefox.esr-102.0",
      "released": "2022-06-23T00:00:00Z"
    },
    {
      "platform": "windows-app",
      "product": "Mozilla Thunderbird (en-US)",
      "fixedVersion": "91.2.0",
      "fix": "Mozilla Thunderbird (en-US) 91.2.0",
      "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird-91.2.0",
      "released": "2021-10-04T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "RHEL 8",
      "fixedVersion": "0:91.2.0-4.el8_4",
      "fix": "RHSA-2021:3755",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-3755",
      "released": "2021-10-11T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox 93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-93.0-build1-0ubuntu0.18.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox 93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-93.0-build1-0ubuntu0.20.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "ol 8",
      "fixedVersion": "0:91.2.0-4.0.1.el8_4",
      "fix": "ELSA-2021-3755",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-3755",
      "released": "2021-10-11T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox-geckodriver 93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-geckodriver-93.0-build1-0ubuntu0.18.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-geckodriver",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox-geckodriver 93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-geckodriver-93.0-build1-0ubuntu0.20.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "firefox-mozsymbols 93.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-firefox-mozsymbols-93.0-build1-0ubuntu0.18.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-mozsymbols",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "firefox-mozsymbols 93.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-firefox-mozsymbols-93.0-build1-0ubuntu0.20.04.1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "RHEL 8",
      "fixedVersion": "0:91.2.0-1.el8_4",
      "fix": "RHSA-2021:3838",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-3838",
      "released": "2021-10-13T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "thunderbird 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-thunderbird-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "thunderbird 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-thunderbird-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "thunderbird 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-thunderbird-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "ol 8",
      "fixedVersion": "0:91.2.0-1.0.1.el8_4",
      "fix": "ELSA-2021-3838",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-3838",
      "released": "2021-10-15T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-gnome-support",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "thunderbird-gnome-support 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-thunderbird-gnome-support-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-gnome-support",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "thunderbird-gnome-support 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-thunderbird-gnome-support-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-gnome-support",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "thunderbird-gnome-support 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-thunderbird-gnome-support-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-mozsymbols",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "thunderbird-mozsymbols 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-thunderbird-mozsymbols-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-mozsymbols",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "thunderbird-mozsymbols 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-thunderbird-mozsymbols-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird-mozsymbols",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "thunderbird-mozsymbols 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-thunderbird-mozsymbols-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-calendar-timezones",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "xul-ext-calendar-timezones 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-xul-ext-calendar-timezones-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-calendar-timezones",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "xul-ext-calendar-timezones 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-xul-ext-calendar-timezones-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-calendar-timezones",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "xul-ext-calendar-timezones 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-xul-ext-calendar-timezones-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-gdata-provider",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "xul-ext-gdata-provider 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-xul-ext-gdata-provider-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-gdata-provider",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "xul-ext-gdata-provider 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-xul-ext-gdata-provider-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-gdata-provider",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "xul-ext-gdata-provider 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-xul-ext-gdata-provider-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-lightning",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "fix": "xul-ext-lightning 1:91.5.0\u002Bbuild1-0ubuntu0.18.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-xul-ext-lightning-1-91.5.0-build1-0ubuntu0.18.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-lightning",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "fix": "xul-ext-lightning 1:91.5.0\u002Bbuild1-0ubuntu0.20.04.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-xul-ext-lightning-1-91.5.0-build1-0ubuntu0.20.04.1",
      "released": "2023-02-16T14:15:00Z"
    },
    {
      "platform": "linux",
      "product": "xul-ext-lightning",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "1:91.3.0\u002Bbuild2-0ubuntu1",
      "fix": "xul-ext-lightning 1:91.3.0\u002Bbuild2-0ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-xul-ext-lightning-1-91.3.0-build2-0ubuntu1",
      "released": "2021-11-02T18:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}