Cisco IOS XE IKEv2 Fragmentation DoS (cisco-sa-20160323-ios-ikev2)

#TRUSTED 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
#TRUST-RSA-SHA256 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(90356);
  script_version("1.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/03");

  script_cve_id("CVE-2016-1344");
  script_xref(name:"TRA", value:"TRA-2016-06");
  script_xref(name:"CISCO-BUG-ID", value:"CSCux38417");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20160323-ios-ikev2");

  script_name(english:"Cisco IOS XE IKEv2 Fragmentation DoS (cisco-sa-20160323-ios-ikev2)");
  script_summary(english:"Checks the IOS XE version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version, the Cisco IOS XE software
running on the remote device is affected by a denial of service
vulnerability in the Internet Key Exchange version 2 (IKEv2) subsystem
due to improper handling of fragmented IKEv2 packets. An
unauthenticated, remote attacker can exploit this issue, via specially
crafted UDP packets, to cause the device to reload.

Note that this issue only affects devices with IKEv2 fragmentation
enabled and is configured for any VPN type based on IKEv2.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160323-ios-ikev2
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9feec3b3");
  script_set_attribute(attribute:"see_also", value:"https://www.tenable.com/security/research/tra-2016-06");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCux38417. Alternatively, apply the workaround as referenced in the
vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-1344");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/03/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/03/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/04/06");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:ios_xe");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CISCO");

  script_copyright(english:"This script is Copyright (C) 2016-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_ios_xe_version.nasl");
  script_require_keys("Host/Cisco/IOS-XE/Version");

  exit(0);
}

include("audit.inc");
include("cisco_func.inc");
include("cisco_kb_cmd_func.inc");

version = get_kb_item_or_exit("Host/Cisco/IOS-XE/Version");

fix = '';
flag = 0;

# Check for vuln version
if ( ver == '3.8.0E' ) flag++;
if ( ver == '3.8.1E' ) flag++;
if ( ver == '3.3.0S' ) flag++;
if ( ver == '3.3.1S' ) flag++;
if ( ver == '3.3.2S' ) flag++;
if ( ver == '3.3.0SG' ) flag++;
if ( ver == '3.3.1SG' ) flag++;
if ( ver == '3.3.2SG' ) flag++;
if ( ver == '3.3.0XO' ) flag++;
if ( ver == '3.3.1XO' ) flag++;
if ( ver == '3.3.2XO' ) flag++;
if ( ver == '3.4.0S' ) flag++;
if ( ver == '3.4.0aS' ) flag++;
if ( ver == '3.4.1S' ) flag++;
if ( ver == '3.4.2S' ) flag++;
if ( ver == '3.4.3S' ) flag++;
if ( ver == '3.4.4S' ) flag++;
if ( ver == '3.4.5S' ) flag++;
if ( ver == '3.4.6S' ) flag++;
if ( ver == '3.4.0SG' ) flag++;
if ( ver == '3.4.1SG' ) flag++;
if ( ver == '3.4.2SG' ) flag++;
if ( ver == '3.4.3SG' ) flag++;
if ( ver == '3.4.4SG' ) flag++;
if ( ver == '3.4.5SG' ) flag++;
if ( ver == '3.4.6SG' ) flag++;
if ( ver == '3.4.7SG' ) flag++;
if ( ver == '3.5.0E' ) flag++;
if ( ver == '3.5.1E' ) flag++;
if ( ver == '3.5.2E' ) flag++;
if ( ver == '3.5.3E' ) flag++;
if ( ver == '3.5.0S' ) flag++;
if ( ver == '3.5.1S' ) flag++;
if ( ver == '3.5.2S' ) flag++;
if ( ver == '3.6.0E' ) flag++;
if ( ver == '3.6.1E' ) flag++;
if ( ver == '3.6.2aE' ) flag++;
if ( ver == '3.6.2E' ) flag++;
if ( ver == '3.6.3E' ) flag++;
if ( ver == '3.6.0S' ) flag++;
if ( ver == '3.6.1S' ) flag++;
if ( ver == '3.6.2S' ) flag++;
if ( ver == '3.7.3E' ) flag++;
if ( ver == '3.7.0E' ) flag++;
if ( ver == '3.7.1E' ) flag++;
if ( ver == '3.7.2E' ) flag++;
if ( ver == '3.7.0S' ) flag++;
if ( ver == '3.7.1S' ) flag++;
if ( ver == '3.7.2S' ) flag++;
if ( ver == '3.7.2tS' ) flag++;
if ( ver == '3.7.3S' ) flag++;
if ( ver == '3.7.4S' ) flag++;
if ( ver == '3.7.4aS' ) flag++;
if ( ver == '3.7.5S' ) flag++;
if ( ver == '3.7.6S' ) flag++;
if ( ver == '3.7.7S' ) flag++;
if ( ver == '3.8.0S' ) flag++;
if ( ver == '3.8.1S' ) flag++;
if ( ver == '3.8.2S' ) flag++;
if ( ver == '3.9.0S' ) flag++;
if ( ver == '3.9.0aS' ) flag++;
if ( ver == '3.9.1S' ) flag++;
if ( ver == '3.9.1aS' ) flag++;
if ( ver == '3.9.2S' ) flag++;
if ( ver == '3.10.0S' ) flag++;
if ( ver == '3.10.1S' ) flag++;
if ( ver == '3.10.1xbS' ) flag++;
if ( ver == '3.10.2S' ) flag++;
if ( ver == '3.10.3S' ) flag++;
if ( ver == '3.10.4S' ) flag++;
if ( ver == '3.10.5S' ) flag++;
if ( ver == '3.10.6S' ) flag++;
if ( ver == '3.11.0S' ) flag++;
if ( ver == '3.11.1S' ) flag++;
if ( ver == '3.11.2S' ) flag++;
if ( ver == '3.11.3S' ) flag++;
if ( ver == '3.11.4S' ) flag++;
if ( ver == '3.12.0S' ) flag++;
if ( ver == '3.12.1S' ) flag++;
if ( ver == '3.12.4S' ) flag++;
if ( ver == '3.12.2S' ) flag++;
if ( ver == '3.12.3S' ) flag++;
if ( ver == '3.13.2aS' ) flag++;
if ( ver == '3.13.0S' ) flag++;
if ( ver == '3.13.0aS' ) flag++;
if ( ver == '3.13.1S' ) flag++;
if ( ver == '3.13.2S' ) flag++;
if ( ver == '3.13.3S' ) flag++;
if ( ver == '3.13.4S' ) flag++;
if ( ver == '3.14.0S' ) flag++;
if ( ver == '3.14.1S' ) flag++;
if ( ver == '3.14.2S' ) flag++;
if ( ver == '3.14.3S' ) flag++;
if ( ver == '3.15.1cS' ) flag++;
if ( ver == '3.15.0S' ) flag++;
if ( ver == '3.15.1S' ) flag++;
if ( ver == '3.15.2S' ) flag++;
if ( ver == '3.17.0S' ) flag++;
if ( ver == '3.16.0S' ) flag++;
if ( ver == '3.16.0cS' ) flag++;
if ( ver == '3.16.1S' ) flag++;
if ( ver == '3.16.1aS' ) flag++;

# Check that IKEv2 fragmentation or IKEv2 is running
if (flag && get_kb_item("Host/local_checks_enabled"))
{
  flag = 0;

  # Check for condition 1, IKEv2 fragmentation
  buf = cisco_command_kb_item("Host/Cisco/Config/show_running-config","show running-config");
  if (check_cisco_result(buf))
  {
    if ("crypto ikev2 fragmentation" >< buf) flag = 1;
  }
  else if (cisco_needs_enable(buf))
  {
    flag = 1;
    override = 1;
  }

  # Check for condition 2, IKEv2 is running
  if (flag)
  {
    flag = 0;

    pat = "(\d+.\d+.\d+.\d+|.*:.*|UNKNOWN|--any--)\s+(500|848|4500)\s";
    buf = cisco_command_kb_item("Host/Cisco/Config/show_ip_sockets","show ip sockets");
    if (!flag)
    {
      if (check_cisco_result(buf))
      {
        if (
          preg(multiline:TRUE, pattern:pat, string:buf)
        ) flag = 1;
      }
      else if (cisco_needs_enable(buf))
      {
        flag = 1;
        override = 1;
      }
    }

    if (!flag)
    {
      buf = cisco_command_kb_item("Host/Cisco/Config/show_udp","show udp");
      if (check_cisco_result(buf))
      {
        if (
          preg(multiline:TRUE, pattern:pat, string:buf)
        ) flag = 1;
      }
      else if (cisco_needs_enable(buf))
      {
        flag = 1;
        override = 1;
      }
    }
  }
}

if (flag)
{
  if (report_verbosity > 0)
  {
    report =
      '\n  Cisco bug ID      : CSCux38417' +
      '\n  Installed release : ' + version +
      '\n';
    security_hole(port:0, extra:report + cisco_caveat(override));
    exit(0);
  }
  else security_hole(port:0, extra:cisco_caveat(override));
}
else audit(AUDIT_HOST_NOT, "affected");