{
  "cveId": "CVE-2021-23840",
  "url": "https://patchblox.com/security/cve/CVE-2021-23840",
  "summary": "CVE-2021-23840 is fixed in 17 products on 1 platform, first by libssl1.0.0 1.0.2n-1ubuntu5.6, released February 16, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libssl3t64: Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate mayoverflow the output length argument in some cas...",
  "description": "Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate mayoverflow the output length argument in some cases where the input length isclose to the maximum permissable length for an integer on the platform. Insuch cases the return value from the function call will be 1 (indicatingsuccess), but the output length value will be negative. This could causeapplications to behave incorrectly or crash. OpenSSL versions 1.1.1i andbelow are affected by this issue. Users of these versions should upgrade toOpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by thisissue. However OpenSSL 1.0.2 is out of support and no longer receivingpublic updates. Premium support customers of OpenSSL 1.0.2 should upgradeto 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j(Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).",
  "published": "2021-02-16T09:15:00Z",
  "severity": "Low",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.50732,
  "epssPercentile": 0.98929,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "edk2",
      "release": "rocky 8",
      "fixedVersion": "0:20210527gite1999b264f1f-3.el8",
      "fix": "RLSA-2021:4198",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2021-4198",
      "released": "2021-11-09T08:37:02Z"
    },
    {
      "platform": "linux",
      "product": "edk2-aarch64",
      "release": "RHEL 8",
      "fixedVersion": "0:20210527gite1999b264f1f-3.el8",
      "fix": "RHSA-2021:4198",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4198",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "edk2-ovmf",
      "release": "RHEL 8",
      "fixedVersion": "0:20210527gite1999b264f1f-3.el8",
      "fix": "RHSA-2021:4198",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4198",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "edk2-ovmf",
      "release": "almalinux 8",
      "fixedVersion": "20210527gite1999b264f1f-3.el8",
      "fix": "ALSA-2021:4198",
      "url": "https://patchblox.com/security/fix/linux/alsa-2021-4198",
      "released": "2021-11-09T08:37:02Z"
    },
    {
      "platform": "linux",
      "product": "libssl1.0.0",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.0.2n-1ubuntu5.6",
      "fix": "libssl1.0.0 1.0.2n-1ubuntu5.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libssl1.0.0-1.0.2n-1ubuntu5.6",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libssl1.1",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.1.1-1ubuntu2.1~18.04.8",
      "fix": "libssl1.1 1.1.1-1ubuntu2.1~18.04.8",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libssl1.1-1.1.1-1ubuntu2.1-18.04.8",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libssl1.1",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1.1.1f-1ubuntu2.2",
      "fix": "libssl1.1 1.1.1f-1ubuntu2.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libssl1.1-1.1.1f-1ubuntu2.2",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libssl3t64",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "1.1.1j-1ubuntu1",
      "fix": "libssl3t64 1.1.1j-1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-libssl3t64-1.1.1j-1ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "libssl3t64",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "1.1.1j-1ubuntu1",
      "fix": "libssl3t64 1.1.1j-1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-libssl3t64-1.1.1j-1ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "RHEL 8",
      "fixedVersion": "1:1.1.1k-4.el8",
      "fix": "RHSA-2021:4424",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4424",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.1.1-1ubuntu2.1~18.04.8",
      "fix": "openssl 1.1.1-1ubuntu2.1~18.04.8",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-openssl-1.1.1-1ubuntu2.1-18.04.8",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "1.1.1f-1ubuntu2.2",
      "fix": "openssl 1.1.1f-1ubuntu2.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-openssl-1.1.1f-1ubuntu2.2",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "1.1.1j-1ubuntu1",
      "fix": "openssl 1.1.1j-1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-openssl-1.1.1j-1ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "1.1.1j-1ubuntu1",
      "fix": "openssl 1.1.1j-1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-openssl-1.1.1j-1ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "rocky 8",
      "fixedVersion": "1:1.1.1k-4.el8",
      "fix": "RLSA-2021:4424",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2021-4424",
      "released": "2021-11-09T09:21:13Z"
    },
    {
      "platform": "linux",
      "product": "openssl-debugsource",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-devel",
      "release": "RHEL 8",
      "fixedVersion": "1:1.1.1k-4.el8",
      "fix": "RHSA-2021:4424",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4424",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-devel",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-libs",
      "release": "RHEL 8",
      "fixedVersion": "1:1.1.1k-4.el8",
      "fix": "RHSA-2021:4424",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4424",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-libs",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-perl",
      "release": "RHEL 8",
      "fixedVersion": "1:1.1.1k-4.el8",
      "fix": "RHSA-2021:4424",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4424",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-perl",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-static",
      "release": "ol 8",
      "fixedVersion": "2:1.1.1k-4.ksplice1.el8",
      "fix": "ELSA-2021-9561",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-9561",
      "released": "2021-11-23T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl1.0",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "1.0.2n-1ubuntu5.6",
      "fix": "openssl1.0 1.0.2n-1ubuntu5.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-openssl1.0-1.0.2n-1ubuntu5.6",
      "released": "2021-02-16T09:15:00Z"
    },
    {
      "platform": "linux",
      "product": "ovmf",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "0~20191122.bd85bf54-2ubuntu3.3",
      "fix": "ovmf 0~20191122.bd85bf54-2ubuntu3.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-ovmf-0-20191122.bd85bf54-2ubuntu3.3",
      "released": "2021-09-13T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "qemu-efi",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "0~20191122.bd85bf54-2ubuntu3.3",
      "fix": "qemu-efi 0~20191122.bd85bf54-2ubuntu3.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-qemu-efi-0-20191122.bd85bf54-2ubuntu3.3",
      "released": "2021-09-13T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "qemu-efi-aarch64",
      "release": "Ubuntu 20.04 LTS (focal)",
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      "fix": "qemu-efi-aarch64 0~20191122.bd85bf54-2ubuntu3.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-qemu-efi-aarch64-0-20191122.bd85bf54-2ubuntu3.3",
      "released": "2021-09-13T17:00:00Z"
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    {
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      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-qemu-efi-arm-0-20191122.bd85bf54-2ubuntu3.3",
      "released": "2021-09-13T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}