{
  "threat_severity" : "Important",
  "public_date" : "2016-07-12T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: challenge ACK counter information disclosure.",
    "id" : "1354708",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1354708"
  },
  "cvss" : {
    "cvss_base_score" : "5.8",
    "cvss_scoring_vector" : "AV:N/AC:M/Au:N/C:N/I:P/A:P",
    "status" : "verified"
  },
  "cvss3" : {
    "cvss3_base_score" : "4.8",
    "cvss3_scoring_vector" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L",
    "status" : "verified"
  },
  "cwe" : "CWE-203",
  "details" : [ "net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly determine the rate of challenge ACK segments, which makes it easier for remote attackers to hijack TCP sessions via a blind in-window attack.", "It was found that the RFC 5961 challenge ACK rate limiting as implemented in the Linux kernel's networking subsystem allowed an off-path attacker to leak certain information about a given connection by creating congestion on the global challenge ACK rate limit counter and then measuring the changes by probing packets. An off-path attacker could use this flaw to either terminate TCP connection and/or inject payload into non-secured TCP connection between two endpoints on the network." ],
  "statement" : "This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 4 and 5.",
  "acknowledgement" : "Red Hat would like to thank Yue Cao (Cyber Security Group of the CS department of University of California in Riverside) for reporting this issue.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "release_date" : "2016-08-23T00:00:00Z",
    "advisory" : "RHSA-2016:1664",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6",
    "package" : "kernel-0:2.6.32-642.4.2.el6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6.5 Advanced Update Support",
    "release_date" : "2016-09-06T00:00:00Z",
    "advisory" : "RHSA-2016:1814",
    "cpe" : "cpe:/o:redhat:rhel_aus:6.5",
    "package" : "kernel-0:2.6.32-431.73.2.el6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6.6 Extended Update Support",
    "release_date" : "2016-09-27T00:00:00Z",
    "advisory" : "RHSA-2016:1939",
    "cpe" : "cpe:/o:redhat:rhel_eus:6.6",
    "package" : "kernel-0:2.6.32-504.52.1.el6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6.7 Extended Update Support",
    "release_date" : "2016-09-06T00:00:00Z",
    "advisory" : "RHSA-2016:1815",
    "cpe" : "cpe:/o:redhat:rhel_eus:6.7",
    "package" : "kernel-0:2.6.32-573.34.1.el6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2016-08-18T00:00:00Z",
    "advisory" : "RHSA-2016:1632",
    "cpe" : "cpe:/a:redhat:rhel_extras_rt:7",
    "package" : "kernel-rt-0:3.10.0-327.28.3.rt56.235.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2016-08-18T00:00:00Z",
    "advisory" : "RHSA-2016:1633",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "kernel-0:3.10.0-327.28.3.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.1 Extended Update Support",
    "release_date" : "2016-08-23T00:00:00Z",
    "advisory" : "RHSA-2016:1657",
    "cpe" : "cpe:/o:redhat:rhel_eus:7.1",
    "package" : "kernel-0:3.10.0-229.40.1.ael7b"
  }, {
    "product_name" : "Red Hat Enterprise MRG 2",
    "release_date" : "2016-08-18T00:00:00Z",
    "advisory" : "RHSA-2016:1631",
    "cpe" : "cpe:/a:redhat:enterprise_mrg:2:server:el6",
    "package" : "kernel-rt-1:3.10.0-327.rt56.195.el6rt"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 4",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 5",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2016-5696\nhttps://nvd.nist.gov/vuln/detail/CVE-2016-5696\nhttp://lwn.net/Articles/696868/" ],
  "csaw" : true,
  "name" : "CVE-2016-5696"
}