{
  "threat_severity" : "Moderate",
  "public_date" : "2015-07-02T00:00:00Z",
  "bugzilla" : {
    "description" : "NSS: incorrectly permited skipping of ServerKeyExchange (MFSA 2015-71)",
    "id" : "1236967",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1236967"
  },
  "cvss" : {
    "cvss_base_score" : "5.1",
    "cvss_scoring_vector" : "AV:N/AC:H/Au:N/C:P/I:P/A:P",
    "status" : "verified"
  },
  "cwe" : "CWE-358",
  "details" : [ "Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a \"SMACK SKIP-TLS\" issue.", "It was found that NSS permitted skipping of the ServerKeyExchange packet during a handshake involving ECDHE (Elliptic Curve Diffie-Hellman key Exchange). A remote attacker could use this flaw to bypass the forward-secrecy of a TLS/SSL connection." ],
  "acknowledgement" : "Red Hat would like to thank Mozilla project for reporting this issue. Upstream acknowledges Karthikeyan Bhargavan as the original reporter.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 5",
    "release_date" : "2015-08-24T00:00:00Z",
    "advisory" : "RHSA-2015:1664",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5",
    "package" : "nss-0:3.19.1-1.el5_11"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "release_date" : "2015-06-25T00:00:00Z",
    "advisory" : "RHSA-2015:1185",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6",
    "package" : "nss-0:3.19.1-3.el6_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "release_date" : "2015-06-25T00:00:00Z",
    "advisory" : "RHSA-2015:1185",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6",
    "package" : "nss-util-0:3.19.1-1.el6_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2015-06-25T00:00:00Z",
    "advisory" : "RHSA-2015:1185",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "nss-0:3.19.1-3.ael7b_1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2015-06-25T00:00:00Z",
    "advisory" : "RHSA-2015:1185",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "nss-util-0:3.19.1-1.ael7b_1"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 5",
    "fix_state" : "Not affected",
    "package_name" : "gnutls",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 5",
    "fix_state" : "Not affected",
    "package_name" : "openssl",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "gnutls",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "openssl",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "gnutls",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "openssl",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2015-2721\nhttps://nvd.nist.gov/vuln/detail/CVE-2015-2721\nhttp://www.mozilla.org/security/announce/2015/mfsa2015-71.html" ],
  "name" : "CVE-2015-2721",
  "csaw" : false
}