{
  "threat_severity" : "Important",
  "public_date" : "2020-10-11T00:00:00Z",
  "bugzilla" : {
    "description" : "stunnel: client certificate not correctly verified when redirect and verifyChain options are used",
    "id" : "1925226",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1925226"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
    "status" : "verified"
  },
  "cwe" : "CWE-295",
  "details" : [ "A flaw was found in stunnel before 5.57, where it improperly validates client certificates when it is configured to use both redirect and verifyChain options. This flaw allows an attacker with a certificate signed by a Certificate Authority, which is not the one accepted by the stunnel server, to access the tunneled service instead of being redirected to the address specified in the redirect option. The highest threat from this vulnerability is to confidentiality.", "A flaw was found in stunnel, where it improperly validates client certificates when it is configured to use both redirect and verifyChain options. This flaw allows an attacker with a certificate signed by a Certificate Authority, which is not the one accepted by the stunnel server, to access the tunneled service instead of being redirected to the address specified in the redirect option. The highest threat from this vulnerability is to confidentiality." ],
  "statement" : "This issue did not affect the versions of stunnel as shipped with Red Hat Enterprise Linux 5, 6, and 7 as they did not include support for the \"redirect\" option.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2021-02-22T00:00:00Z",
    "advisory" : "RHSA-2021:0618",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "stunnel-0:5.56-5.el8_3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.1 Extended Update Support",
    "release_date" : "2021-02-22T00:00:00Z",
    "advisory" : "RHSA-2021:0620",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.1",
    "package" : "stunnel-0:5.48-6.el8_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Extended Update Support",
    "release_date" : "2021-02-22T00:00:00Z",
    "advisory" : "RHSA-2021:0619",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.2",
    "package" : "stunnel-0:5.48-6.el8_2"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 5",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2021-20230\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-20230" ],
  "name" : "CVE-2021-20230",
  "csaw" : false
}