{
  "cveId": "CVE-2021-43534",
  "url": "https://patchblox.com/security/cve/CVE-2021-43534",
  "summary": "CVE-2021-43534 is fixed in 10 products on 2 platforms, first by Mozilla Thunderbird (en-US) 91.3.0, released November 1, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "Mozilla Firefox ESR and 3 others: Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox\u2026",
  "description": "Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. 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 94, Thunderbird \u003C 91.3, and Firefox ESR \u003C 91.3.",
  "published": "2021-11-03T00:00:00Z",
  "severity": "Important",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
  "epss": 0.01248,
  "epssPercentile": 0.69525,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://nvd.nist.gov/vuln/detail/CVE-2021-43534",
  "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": "91.3.0",
      "fix": "Mozilla Thunderbird (en-US) 91.3.0",
      "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird-91.3.0",
      "released": "2021-11-01T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox",
      "release": "RHEL 8",
      "fixedVersion": "0:91.3.0-1.el8_4",
      "fix": "RHSA-2021:4123",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4123",
      "released": "2021-11-03T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "firefox-esr",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "91.3.0esr-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "firefox-esr",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "91.3.0esr-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "firefox-esr",
      "release": "Debian 14",
      "fixedVersion": "91.3.0esr-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "1:91.3.0-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1:91.3.0-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "Debian 14",
      "fixedVersion": "1:91.3.0-1",
      "fix": "DEBIAN-CVE-2021-43534",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-43534",
      "released": "2021-12-08T22:15:09Z"
    },
    {
      "platform": "linux",
      "product": "thunderbird",
      "release": "RHEL 8",
      "fixedVersion": "0:91.3.0-2.el8_4",
      "fix": "RHSA-2021:4130",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4130",
      "released": "2021-11-04T00:00:00Z"
    },
    {
      "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-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-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": "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-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-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"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}