{
  "threat_severity" : "Critical",
  "public_date" : "2021-12-01T16:00:00Z",
  "bugzilla" : {
    "description" : "nss: Memory corruption in decodeECorDsaSignature with DSA signatures (and RSA-PSS)",
    "id" : "2024370",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2024370"
  },
  "cvss3" : {
    "cvss3_base_score" : "9.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-120",
  "details" : [ "NSS (Network Security Services) versions prior to 3.73 or 3.68.1 ESR are vulnerable to a heap overflow when handling DER-encoded DSA or RSA-PSS signatures. Applications using NSS for handling signatures encoded within CMS, S/MIME, PKCS \\#7, or PKCS \\#12 are likely to be impacted. Applications using NSS for certificate validation or other TLS, X.509, OCSP or CRL functionality may be impacted, depending on how they configure NSS. *Note: This vulnerability does NOT impact Mozilla Firefox.* However, email clients and PDF viewers that use NSS for signature verification, such as Thunderbird, LibreOffice, Evolution and Evince are believed to be impacted. This vulnerability affects NSS < 3.73 and NSS < 3.68.1.", "A remote code execution flaw was found in the way NSS verifies certificates. This flaw allows an attacker posing as an SSL/TLS server to trigger this issue in a client application compiled with NSS when it tries to initiate an SSL/TLS connection.  Similarly, a server application compiled with NSS, which processes client certificates, can receive a malicious certificate via a client, triggering the flaw. The highest threat to this vulnerability is confidentiality, integrity, as well as system availability." ],
  "statement" : "The issue is not limited to TLS. Any applications that use NSS certificate verification are vulnerable; S/MIME is impacted as well.  Similarly, a server application compiled with NSS, which processes client certificates, can receive a malicious certificate via a client.\nFirefox is not vulnerable to this flaw as it uses the mozilla::pkix for certificate verification. Thunderbird is affected when parsing email with the S/MIME signature.  Thunderbird on Red Hat Enterprise Linux 8.4 and later does not need to be updated since it uses the system NSS library, but earlier Red Hat Enterprise Linux 8 extended life streams will need to update Thunderbird as well as NSS.",
  "acknowledgement" : "Red Hat would like to thank Tavis Ormandy (Project Zero) for reporting this issue. Upstream acknowledges the Mozilla project as the original reporter.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 6 Extended Lifecycle Support",
    "release_date" : "2021-12-01T00:00:00Z",
    "advisory" : "RHSA-2021:4907",
    "cpe" : "cpe:/o:redhat:rhel_els:6",
    "package" : "nss-0:3.44.0-12.el6_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2021-12-01T00:00:00Z",
    "advisory" : "RHSA-2021:4904",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "nss-0:3.67.0-4.el7_9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.3 Advanced Update Support",
    "release_date" : "2021-12-07T00:00:00Z",
    "advisory" : "RHSA-2021:4994",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.3",
    "package" : "nss-0:3.28.4-2.el7_3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.4 Advanced Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4932",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.4",
    "package" : "nss-0:3.28.4-18.el7_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.6 Advanced Update Support(Disable again in 2026 - SPRHEL-7118)",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4933",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.6",
    "package" : "nss-0:3.36.0-10.2.el7_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.6 Telco Extended Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4933",
    "cpe" : "cpe:/o:redhat:rhel_tus:7.6",
    "package" : "nss-0:3.36.0-10.2.el7_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.6 Update Services for SAP Solutions",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4933",
    "cpe" : "cpe:/o:redhat:rhel_e4s:7.6",
    "package" : "nss-0:3.36.0-10.2.el7_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.7 Advanced Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4946",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.7",
    "package" : "nss-0:3.44.0-8.el7_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.7 Telco Extended Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4946",
    "cpe" : "cpe:/o:redhat:rhel_tus:7.7",
    "package" : "nss-0:3.44.0-8.el7_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4946",
    "cpe" : "cpe:/o:redhat:rhel_e4s:7.7",
    "package" : "nss-0:3.44.0-8.el7_7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2021-12-01T00:00:00Z",
    "advisory" : "RHSA-2021:4903",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8",
    "package" : "nss-0:3.67.0-7.el8_5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.1 Extended Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4953",
    "cpe" : "cpe:/a:redhat:rhel_eus:8.1",
    "package" : "nss-0:3.44.0-10.el8_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4969",
    "cpe" : "cpe:/a:redhat:rhel_e4s:8.1",
    "package" : "thunderbird-0:91.3.0-3.el8_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Extended Update Support",
    "release_date" : "2021-12-02T00:00:00Z",
    "advisory" : "RHSA-2021:4919",
    "cpe" : "cpe:/a:redhat:rhel_eus:8.2",
    "package" : "nss-0:3.53.1-12.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Extended Update Support",
    "release_date" : "2021-12-06T00:00:00Z",
    "advisory" : "RHSA-2021:4954",
    "cpe" : "cpe:/a:redhat:rhel_eus:8.2",
    "package" : "thunderbird-0:91.3.0-3.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Extended Update Support",
    "release_date" : "2021-12-02T00:00:00Z",
    "advisory" : "RHSA-2021:4909",
    "cpe" : "cpe:/a:redhat:rhel_eus:8.4",
    "package" : "nss-0:3.67.0-7.el8_4"
  }, {
    "product_name" : "Red Hat Virtualization 4 for Red Hat Enterprise Linux 7",
    "release_date" : "2021-12-08T00:00:00Z",
    "advisory" : "RHSA-2021:5035",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7::hypervisor",
    "package" : "redhat-virtualization-host-0:4.3.20-20211202.1.el7_9"
  }, {
    "product_name" : "Red Hat Virtualization 4 for Red Hat Enterprise Linux 8",
    "release_date" : "2021-12-08T00:00:00Z",
    "advisory" : "RHSA-2021:5006",
    "cpe" : "cpe:/o:redhat:rhev_hypervisor:4.4::el8",
    "package" : "redhat-virtualization-host-0:4.4.9-202112061811_8.5"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "thunderbird",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "firefox",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "thunderbird",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "firefox",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "thunderbird",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "firefox",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "nss",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "thunderbird",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2021-43527\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-43527\nhttps://googleprojectzero.blogspot.com/2021/12/this-shouldnt-have-happened.html\nhttps://www.mozilla.org/en-US/security/advisories/mfsa2021-51/" ],
  "csaw" : true,
  "name" : "CVE-2021-43527",
  "mitigation" : {
    "value" : "Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.",
    "lang" : "en:us"
  }
}