Vulnerabilities > CVE-2017-3864 - Unspecified vulnerability in Cisco IOS

047910
CVSS 8.6 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
cisco
nessus
NVD
Published: 2017-03-22
Updated: 2024-11-21

Summary

A vulnerability in the DHCP client implementation of Cisco IOS (12.2, 12.4, and 15.0 through 15.6) and Cisco IOS XE (3.3 through 3.7) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability occurs during the parsing of a crafted DHCP packet. An attacker could exploit this vulnerability by sending crafted DHCP packets to an affected device that is configured as a DHCP client. A successful exploit could allow the attacker to cause a reload of an affected device, resulting in a DoS condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or IOS XE Software and using a specific DHCP client configuration. Cisco Bug IDs: CSCuu43892.

Vulnerable Configurations

Part Description Count
OS
Cisco
1324

Nessus

  • NASL familyCISCO
    NASL idCISCO-SA-20170322-DHCPC-IOSXE.NASL
    descriptionAccording 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 DHCP client implementation when parsing DHCP packets. An unauthenticated, remote attacker can exploit this issue, via specially crafted DHCP packets, to cause the device to reload.
    last seen2020-06-01
    modified2020-06-02
    plugin id99027
    published2017-03-28
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/99027
    titleCisco IOS XE DHCP Client DoS (cisco-sa-20170322-dhcpc)
    code
    #TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(99027);
  script_version("1.9");
  script_cvs_date("Date: 2019/11/13");

  script_cve_id("CVE-2017-3864");
  script_bugtraq_id(97012);
  script_xref(name:"CISCO-BUG-ID", value:"CSCuu43892");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20170322-dhcpc");

  script_name(english:"Cisco IOS XE DHCP Client DoS (cisco-sa-20170322-dhcpc)");
  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 DHCP client implementation when parsing DHCP
packets. An unauthenticated, remote attacker can exploit this issue,
via specially crafted DHCP packets, to cause the device to reload.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170322-dhcpc
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0d54a2ce");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuu43892");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCuu43892.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:L/PR:N/UI:N/S:C/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/03/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/03/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/03/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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) 2017-2019 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");

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

flag = 0;

if (
  ver == '3.3.0SE' ||
  ver == '3.3.0XO' ||
  ver == '3.3.1SE' ||
  ver == '3.3.1XO' ||
  ver == '3.3.2SE' ||
  ver == '3.3.2XO' ||
  ver == '3.3.3SE' ||
  ver == '3.3.4SE' ||
  ver == '3.3.5SE' ||
  ver == '3.5.0E' ||
  ver == '3.5.1E' ||
  ver == '3.5.2E' ||
  ver == '3.5.3E' ||
  ver == '3.6.0E' ||
  ver == '3.6.1E' ||
  ver == '3.6.2aE' ||
  ver == '3.6.2E' ||
  ver == '3.6.3E' ||
  ver == '3.6.4E' ||
  ver == '3.7.0E' ||
  ver == '3.7.1E' ||
  ver == '3.7.2E' ||
  ver == '3.7.3E'
)
{
  flag++;
}

cmds = make_list();
# Check that device is configured as a DHCP client
if (flag && get_kb_item("Host/local_checks_enabled"))
{
  flag = 0;
  buf = cisco_command_kb_item("Host/Cisco/Config/show running-config | include dhcp", "show running-config | include dhcp");
  if (check_cisco_result(buf))
  {
    if ("ip address dhcp" >< buf)
    {
      cmds = make_list(cmds, "show running-config | include dhcp");
      # Check if device is configured as a DHCP server or DHCP relay agent
      buf2 =  cisco_command_kb_item("Host/Cisco/Config/show running-config | include helper|(ip dhcp pool)", "show running-config | include helper|(ip dhcp pool)");
      if (check_cisco_result(buf2))
      {
        if (preg(multiline:TRUE, pattern:"ip helper-address [0-9\.]+", string:buf2))
        {
          cmds = make_list(cmds,"show running-config | include helper|(ip dhcp pool)");
          # Check if device is configured to send DHCP Inform/Discover messages
          # If device is confiured to send DHCP Inform and Discover messages
          # then not vuln
          buf3 = cisco_command_kb_item("Host/Cisco/Config/show running-config | include (ip dhcp-client network-discovery)", "show running-config | include (ip dhcp-client network-discovery)");
          if (check_cisco_result(buf3))
          {
            if (preg(multiline:TRUE, pattern:"ip dhcp-client network-discovery informs .* discovers .*", string:buf3))
            {
              flag = 0;
            }
            else
            {
              flag = 1;
              cmds = make_list(cmds,"show running-config | include (ip dhcp-client network-discovery)");
            }
          }
        }
      }
    }
  }
  else if (cisco_needs_enable(buf))
    override = 1;

  if (!flag && !override) audit(AUDIT_OS_CONF_NOT_VULN, "Cisco IOS XE", ver);
}

if (flag || override)
{
  security_report_cisco(
    port     : 0,
    severity : SECURITY_HOLE,
    override : override,
    version  : ver,
    bug_id   : "CSCuu43892",
    cmds     : cmds
  );
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familyCISCO
    NASL idCISCO-SA-20170322-DHCPC-IOS.NASL
    descriptionAccording to its self-reported version, the Cisco IOS software running on the remote device is affected by a denial of service vulnerability in the DHCP client implementation when parsing DHCP packets. An unauthenticated, remote attacker can exploit this issue, via specially crafted DHCP packets, to cause the device to reload.
    last seen2020-06-01
    modified2020-06-02
    plugin id99026
    published2017-03-28
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/99026
    titleCisco IOS DHCP Client DoS (cisco-sa-20170322-dhcpc)
    code
    #TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(99026);
  script_version("1.10");
  script_cvs_date("Date: 2019/11/13");

  script_cve_id("CVE-2017-3864");
  script_bugtraq_id(97012);
  script_xref(name:"CISCO-BUG-ID", value:"CSCuu43892");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20170322-dhcpc");

  script_name(english:"Cisco IOS DHCP Client DoS (cisco-sa-20170322-dhcpc)");
  script_summary(english:"Checks the IOS 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 software running
on the remote device is affected by a denial of service vulnerability
in the DHCP client implementation when parsing DHCP packets. An
unauthenticated, remote attacker can exploit this issue, via specially
crafted DHCP packets, to cause the device to reload.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170322-dhcpc
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0d54a2ce");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuu43892");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCuu43892.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:L/PR:N/UI:N/S:C/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/03/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/03/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/03/28");

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

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

  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_ios_version.nasl");
  script_require_keys("Host/Cisco/IOS/Version");

  exit(0);
}

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

flag = 0;
override = 0;

ver = get_kb_item_or_exit("Host/Cisco/IOS/Version");

# Check for vuln versions
if (
  ver == '12.2(33)MRA' ||
  ver == '12.2(33)MRB' ||
  ver == '12.2(33)MRB1' ||
  ver == '12.2(33)MRB2' ||
  ver == '12.2(33)MRB3' ||
  ver == '12.2(33)MRB4' ||
  ver == '12.2(33)MRB5' ||
  ver == '12.2(33)MRB6' ||
  ver == '12.2(33)SRD' ||
  ver == '12.2(33)SRD1' ||
  ver == '12.2(33)SRD2' ||
  ver == '12.2(33)SRD2a' ||
  ver == '12.2(33)SRD3' ||
  ver == '12.2(33)SRD4' ||
  ver == '12.2(33)SRD5' ||
  ver == '12.2(33)SRD6' ||
  ver == '12.2(33)SRD7' ||
  ver == '12.2(33)SRD8' ||
  ver == '12.2(33)SRE' ||
  ver == '12.2(33)SRE0a' ||
  ver == '12.2(33)SRE1' ||
  ver == '12.2(33)SRE2' ||
  ver == '12.2(33)SXH5' ||
  ver == '12.2(33)SXH6' ||
  ver == '12.2(33)SXH7' ||
  ver == '12.2(33)SXH8' ||
  ver == '12.2(33)SXH8a' ||
  ver == '12.2(33)SXH8b' ||
  ver == '12.2(33)SXI' ||
  ver == '12.2(33)SXI1' ||
  ver == '12.2(33)SXI10' ||
  ver == '12.2(33)SXI11' ||
  ver == '12.2(33)SXI12' ||
  ver == '12.2(33)SXI13' ||
  ver == '12.2(33)SXI14' ||
  ver == '12.2(33)SXI2' ||
  ver == '12.2(33)SXI2a' ||
  ver == '12.2(33)SXI3' ||
  ver == '12.2(33)SXI4' ||
  ver == '12.2(33)SXI4a' ||
  ver == '12.2(33)SXI5' ||
  ver == '12.2(33)SXI6' ||
  ver == '12.2(33)SXI7' ||
  ver == '12.2(33)SXI8' ||
  ver == '12.2(33)SXI8a' ||
  ver == '12.2(33)SXI9' ||
  ver == '12.2(33)SXJ' ||
  ver == '12.2(33)SXJ1' ||
  ver == '12.2(33)SXJ10' ||
  ver == '12.2(33)SXJ2' ||
  ver == '12.2(33)SXJ3' ||
  ver == '12.2(33)SXJ4' ||
  ver == '12.2(33)SXJ5' ||
  ver == '12.2(33)SXJ6' ||
  ver == '12.2(33)SXJ7' ||
  ver == '12.2(33)SXJ8' ||
  ver == '12.2(33)SXJ9' ||
  ver == '12.2(50)SY' ||
  ver == '12.2(50)SY1' ||
  ver == '12.2(50)SY2' ||
  ver == '12.2(50)SY3' ||
  ver == '12.2(50)SY4' ||
  ver == '12.4(15)T10' ||
  ver == '12.4(15)T11' ||
  ver == '12.4(15)T12' ||
  ver == '12.4(15)T13' ||
  ver == '12.4(15)T14' ||
  ver == '12.4(15)T15' ||
  ver == '12.4(15)T16' ||
  ver == '12.4(15)T17' ||
  ver == '12.4(15)T9' ||
  ver == '12.4(15)XZ' ||
  ver == '12.4(15)XZ1' ||
  ver == '12.4(15)XZ2' ||
  ver == '12.4(19)MR' ||
  ver == '12.4(19)MR1' ||
  ver == '12.4(19)MR2' ||
  ver == '12.4(19)MR3' ||
  ver == '12.4(20)MR' ||
  ver == '12.4(20)MR2' ||
  ver == '12.4(20)MRB' ||
  ver == '12.4(20)MRB1' ||
  ver == '12.4(20)T' ||
  ver == '12.4(20)T1' ||
  ver == '12.4(20)T2' ||
  ver == '12.4(20)T3' ||
  ver == '12.4(20)T4' ||
  ver == '12.4(20)T5' ||
  ver == '12.4(20)T6' ||
  ver == '12.4(20)YA' ||
  ver == '12.4(20)YA1' ||
  ver == '12.4(20)YA2' ||
  ver == '12.4(20)YA3' ||
  ver == '12.4(21)' ||
  ver == '12.4(21a)' ||
  ver == '12.4(21a)JA' ||
  ver == '12.4(21a)JA1' ||
  ver == '12.4(21a)JA2' ||
  ver == '12.4(21a)JHA' ||
  ver == '12.4(21a)JHC' ||
  ver == '12.4(21a)JX' ||
  ver == '12.4(21a)JY' ||
  ver == '12.4(22)GC1' ||
  ver == '12.4(22)MD' ||
  ver == '12.4(22)MD1' ||
  ver == '12.4(22)MD2' ||
  ver == '12.4(22)MDA' ||
  ver == '12.4(22)MDA1' ||
  ver == '12.4(22)MDA2' ||
  ver == '12.4(22)MDA3' ||
  ver == '12.4(22)MDA4' ||
  ver == '12.4(22)MDA5' ||
  ver == '12.4(22)MDA6' ||
  ver == '12.4(22)T' ||
  ver == '12.4(22)T1' ||
  ver == '12.4(22)T2' ||
  ver == '12.4(22)T3' ||
  ver == '12.4(22)T4' ||
  ver == '12.4(22)T5' ||
  ver == '12.4(22)XR1' ||
  ver == '12.4(22)XR10' ||
  ver == '12.4(22)XR11' ||
  ver == '12.4(22)XR12' ||
  ver == '12.4(22)XR2' ||
  ver == '12.4(22)XR3' ||
  ver == '12.4(22)XR4' ||
  ver == '12.4(22)XR5' ||
  ver == '12.4(22)XR6' ||
  ver == '12.4(22)XR7' ||
  ver == '12.4(22)XR8' ||
  ver == '12.4(22)XR9' ||
  ver == '12.4(22)YB' ||
  ver == '12.4(22)YB1' ||
  ver == '12.4(22)YB2' ||
  ver == '12.4(22)YB3' ||
  ver == '12.4(22)YB4' ||
  ver == '12.4(22)YB5' ||
  ver == '12.4(22)YB6' ||
  ver == '12.4(22)YB7' ||
  ver == '12.4(22)YB8' ||
  ver == '12.4(22)YD' ||
  ver == '12.4(22)YD1' ||
  ver == '12.4(22)YD2' ||
  ver == '12.4(22)YD3' ||
  ver == '12.4(22)YD4' ||
  ver == '12.4(22)YE' ||
  ver == '12.4(22)YE1' ||
  ver == '12.4(22)YE2' ||
  ver == '12.4(22)YE3' ||
  ver == '12.4(22)YE4' ||
  ver == '12.4(22)YE5' ||
  ver == '12.4(22)YE6' ||
  ver == '12.4(23)' ||
  ver == '12.4(23a)' ||
  ver == '12.4(23b)' ||
  ver == '12.4(23c)JA' ||
  ver == '12.4(23c)JA1' ||
  ver == '12.4(23c)JA10' ||
  ver == '12.4(23c)JA2' ||
  ver == '12.4(23c)JA3' ||
  ver == '12.4(23c)JA4' ||
  ver == '12.4(23c)JA5' ||
  ver == '12.4(23c)JA6' ||
  ver == '12.4(23c)JA7' ||
  ver == '12.4(23c)JA8' ||
  ver == '12.4(23c)JA9' ||
  ver == '12.4(23c)JY' ||
  ver == '12.4(23c)JZ' ||
  ver == '12.4(24)GC1' ||
  ver == '12.4(24)GC3' ||
  ver == '12.4(24)GC3a' ||
  ver == '12.4(24)GC4' ||
  ver == '12.4(24)GC5' ||
  ver == '12.4(24)MD' ||
  ver == '12.4(24)MD1' ||
  ver == '12.4(24)MD2' ||
  ver == '12.4(24)MD3' ||
  ver == '12.4(24)MD4' ||
  ver == '12.4(24)MD5' ||
  ver == '12.4(24)MD6' ||
  ver == '12.4(24)MD7' ||
  ver == '12.4(24)MDA1' ||
  ver == '12.4(24)MDA10' ||
  ver == '12.4(24)MDA11' ||
  ver == '12.4(24)MDA12' ||
  ver == '12.4(24)MDA13' ||
  ver == '12.4(24)MDA2' ||
  ver == '12.4(24)MDA3' ||
  ver == '12.4(24)MDA4' ||
  ver == '12.4(24)MDA5' ||
  ver == '12.4(24)MDA6' ||
  ver == '12.4(24)MDA7' ||
  ver == '12.4(24)MDA8' ||
  ver == '12.4(24)MDA9' ||
  ver == '12.4(24)MDB' ||
  ver == '12.4(24)MDB1' ||
  ver == '12.4(24)MDB10' ||
  ver == '12.4(24)MDB11' ||
  ver == '12.4(24)MDB12' ||
  ver == '12.4(24)MDB13' ||
  ver == '12.4(24)MDB14' ||
  ver == '12.4(24)MDB15' ||
  ver == '12.4(24)MDB16' ||
  ver == '12.4(24)MDB17' ||
  ver == '12.4(24)MDB18' ||
  ver == '12.4(24)MDB19' ||
  ver == '12.4(24)MDB3' ||
  ver == '12.4(24)MDB4' ||
  ver == '12.4(24)MDB5' ||
  ver == '12.4(24)MDB5a' ||
  ver == '12.4(24)MDB6' ||
  ver == '12.4(24)MDB7' ||
  ver == '12.4(24)MDB8' ||
  ver == '12.4(24)MDB9' ||
  ver == '12.4(24)T' ||
  ver == '12.4(24)T1' ||
  ver == '12.4(24)T2' ||
  ver == '12.4(24)T3' ||
  ver == '12.4(24)T3e' ||
  ver == '12.4(24)T3f' ||
  ver == '12.4(24)T4' ||
  ver == '12.4(24)T4a' ||
  ver == '12.4(24)T4b' ||
  ver == '12.4(24)T4c' ||
  ver == '12.4(24)T4d' ||
  ver == '12.4(24)T4e' ||
  ver == '12.4(24)T4f' ||
  ver == '12.4(24)T4l' ||
  ver == '12.4(24)T5' ||
  ver == '12.4(24)T6' ||
  ver == '12.4(24)T7' ||
  ver == '12.4(24)T8' ||
  ver == '12.4(24)YE' ||
  ver == '12.4(24)YE1' ||
  ver == '12.4(24)YE2' ||
  ver == '12.4(24)YE3' ||
  ver == '12.4(24)YE3a' ||
  ver == '12.4(24)YE3b' ||
  ver == '12.4(24)YE3c' ||
  ver == '12.4(24)YE3d' ||
  ver == '12.4(24)YE3e' ||
  ver == '12.4(24)YE4' ||
  ver == '12.4(24)YE5' ||
  ver == '12.4(24)YE6' ||
  ver == '12.4(24)YE7' ||
  ver == '12.4(24)YG1' ||
  ver == '12.4(24)YG2' ||
  ver == '12.4(24)YG3' ||
  ver == '12.4(24)YG4' ||
  ver == '12.4(25)' ||
  ver == '12.4(25a)' ||
  ver == '12.4(25b)' ||
  ver == '12.4(25c)' ||
  ver == '12.4(25d)' ||
  ver == '12.4(25d)JA' ||
  ver == '12.4(25d)JA1' ||
  ver == '12.4(25d)JA2' ||
  ver == '12.4(25d)JAX' ||
  ver == '12.4(25d)JAX1' ||
  ver == '12.4(25e)' ||
  ver == '12.4(25e)JA' ||
  ver == '12.4(25e)JA1' ||
  ver == '12.4(25e)JAL' ||
  ver == '12.4(25e)JAL1' ||
  ver == '12.4(25e)JAL1a' ||
  ver == '12.4(25e)JAL2' ||
  ver == '12.4(25e)JAM' ||
  ver == '12.4(25e)JAM2' ||
  ver == '12.4(25e)JAM3' ||
  ver == '12.4(25e)JAM4' ||
  ver == '12.4(25e)JAM5' ||
  ver == '12.4(25e)JAM6' ||
  ver == '12.4(25e)JAN1' ||
  ver == '12.4(25e)JAO' ||
  ver == '12.4(25e)JAO1' ||
  ver == '12.4(25e)JAO2' ||
  ver == '12.4(25e)JAO3' ||
  ver == '12.4(25e)JAO4' ||
  ver == '12.4(25e)JAO5' ||
  ver == '12.4(25e)JAO6' ||
  ver == '12.4(25e)JAP' ||
  ver == '12.4(25e)JAP1' ||
  ver == '12.4(25e)JAP10' ||
  ver == '12.4(25e)JAP100' ||
  ver == '12.4(25e)JAP26' ||
  ver == '12.4(25e)JAP4' ||
  ver == '12.4(25e)JAP5' ||
  ver == '12.4(25e)JAP6' ||
  ver == '12.4(25e)JAP7' ||
  ver == '12.4(25e)JAP8' ||
  ver == '12.4(25e)JAP9' ||
  ver == '12.4(25e)JAX' ||
  ver == '12.4(25e)JAX1' ||
  ver == '12.4(25e)JAX2' ||
  ver == '12.4(25e)JAZ' ||
  ver == '12.4(25e)JX' ||
  ver == '12.4(25f)' ||
  ver == '12.4(25g)' ||
  ver == '15.0(1)M' ||
  ver == '15.0(1)M1' ||
  ver == '15.0(1)M10' ||
  ver == '15.0(1)M2' ||
  ver == '15.0(1)M3' ||
  ver == '15.0(1)M4' ||
  ver == '15.0(1)M5' ||
  ver == '15.0(1)M6' ||
  ver == '15.0(1)M7' ||
  ver == '15.0(1)M8' ||
  ver == '15.0(1)M9' ||
  ver == '15.0(1)SY' ||
  ver == '15.0(1)SY1' ||
  ver == '15.0(1)SY10' ||
  ver == '15.0(1)SY2' ||
  ver == '15.0(1)SY3' ||
  ver == '15.0(1)SY4' ||
  ver == '15.0(1)SY5' ||
  ver == '15.0(1)SY6' ||
  ver == '15.0(1)SY7' ||
  ver == '15.0(1)SY7a' ||
  ver == '15.0(1)SY8' ||
  ver == '15.0(1)SY9' ||
  ver == '15.0(1)XA' ||
  ver == '15.0(1)XA1' ||
  ver == '15.0(1)XA2' ||
  ver == '15.0(1)XA3' ||
  ver == '15.0(1)XA4' ||
  ver == '15.0(1)XA5' ||
  ver == '15.0(2)EJ' ||
  ver == '15.0(2)EJ1' ||
  ver == '15.0(2)SE10' ||
  ver == '15.0(2)SE3' ||
  ver == '15.0(2)SE4' ||
  ver == '15.0(2)SE5' ||
  ver == '15.0(2)SE6' ||
  ver == '15.0(2)SE7' ||
  ver == '15.0(2)SE8' ||
  ver == '15.0(2)SE9' ||
  ver == '15.0(2a)SE9' ||
  ver == '15.1(1)SY' ||
  ver == '15.1(1)SY1' ||
  ver == '15.1(1)SY2' ||
  ver == '15.1(1)SY3' ||
  ver == '15.1(1)SY4' ||
  ver == '15.1(1)SY5' ||
  ver == '15.1(1)SY6' ||
  ver == '15.1(1)T' ||
  ver == '15.1(1)T1' ||
  ver == '15.1(1)T2' ||
  ver == '15.1(1)T3' ||
  ver == '15.1(1)T4' ||
  ver == '15.1(1)T5' ||
  ver == '15.1(1)XB' ||
  ver == '15.1(2)GC' ||
  ver == '15.1(2)GC1' ||
  ver == '15.1(2)GC2' ||
  ver == '15.1(2)SY' ||
  ver == '15.1(2)SY1' ||
  ver == '15.1(2)SY2' ||
  ver == '15.1(2)SY3' ||
  ver == '15.1(2)SY4' ||
  ver == '15.1(2)SY4a' ||
  ver == '15.1(2)SY5' ||
  ver == '15.1(2)SY6' ||
  ver == '15.1(2)SY7' ||
  ver == '15.1(2)T' ||
  ver == '15.1(2)T0a' ||
  ver == '15.1(2)T1' ||
  ver == '15.1(2)T2' ||
  ver == '15.1(2)T2a' ||
  ver == '15.1(2)T3' ||
  ver == '15.1(2)T4' ||
  ver == '15.1(2)T5' ||
  ver == '15.1(3)T' ||
  ver == '15.1(3)T1' ||
  ver == '15.1(3)T2' ||
  ver == '15.1(3)T3' ||
  ver == '15.1(3)T4' ||
  ver == '15.1(4)GC' ||
  ver == '15.1(4)GC1' ||
  ver == '15.1(4)GC2' ||
  ver == '15.1(4)M' ||
  ver == '15.1(4)M1' ||
  ver == '15.1(4)M10' ||
  ver == '15.1(4)M2' ||
  ver == '15.1(4)M3' ||
  ver == '15.1(4)M3a' ||
  ver == '15.1(4)M4' ||
  ver == '15.1(4)M5' ||
  ver == '15.1(4)M6' ||
  ver == '15.1(4)M7' ||
  ver == '15.1(4)M8' ||
  ver == '15.1(4)M9' ||
  ver == '15.2(1)E' ||
  ver == '15.2(1)E1' ||
  ver == '15.2(1)E2' ||
  ver == '15.2(1)E3' ||
  ver == '15.2(1)EY' ||
  ver == '15.2(1)GC' ||
  ver == '15.2(1)GC1' ||
  ver == '15.2(1)GC2' ||
  ver == '15.2(1)SY' ||
  ver == '15.2(1)SY0a' ||
  ver == '15.2(1)SY1' ||
  ver == '15.2(1)SY1a' ||
  ver == '15.2(1)SY2' ||
  ver == '15.2(1)T' ||
  ver == '15.2(1)T1' ||
  ver == '15.2(1)T2' ||
  ver == '15.2(1)T3' ||
  ver == '15.2(1)T3a' ||
  ver == '15.2(1)T4' ||
  ver == '15.2(2)E' ||
  ver == '15.2(2)E1' ||
  ver == '15.2(2)E2' ||
  ver == '15.2(2)E4' ||
  ver == '15.2(2)EB' ||
  ver == '15.2(2)EB1' ||
  ver == '15.2(2)EB2' ||
  ver == '15.2(2)GC' ||
  ver == '15.2(2)JA' ||
  ver == '15.2(2)JA1' ||
  ver == '15.2(2)JAX' ||
  ver == '15.2(2)JAX1' ||
  ver == '15.2(2)JB' ||
  ver == '15.2(2)JB2' ||
  ver == '15.2(2)JB3' ||
  ver == '15.2(2)JB4' ||
  ver == '15.2(2)JB5' ||
  ver == '15.2(2)JB6' ||
  ver == '15.2(2)SY' ||
  ver == '15.2(2)SY1' ||
  ver == '15.2(2)T' ||
  ver == '15.2(2)T1' ||
  ver == '15.2(2)T2' ||
  ver == '15.2(2)T3' ||
  ver == '15.2(2)T4' ||
  ver == '15.2(2a)E1' ||
  ver == '15.2(3)E' ||
  ver == '15.2(3)E1' ||
  ver == '15.2(3)E2' ||
  ver == '15.2(3)E3' ||
  ver == '15.2(3)GC' ||
  ver == '15.2(3)GC1' ||
  ver == '15.2(3)T' ||
  ver == '15.2(3)T1' ||
  ver == '15.2(3)T2' ||
  ver == '15.2(3)T3' ||
  ver == '15.2(3)T4' ||
  ver == '15.2(3a)E' ||
  ver == '15.2(3m)E2' ||
  ver == '15.2(4)GC' ||
  ver == '15.2(4)GC1' ||
  ver == '15.2(4)GC2' ||
  ver == '15.2(4)GC3' ||
  ver == '15.2(4)JA' ||
  ver == '15.2(4)JA1' ||
  ver == '15.2(4)JB' ||
  ver == '15.2(4)JB1' ||
  ver == '15.2(4)JB2' ||
  ver == '15.2(4)JB3' ||
  ver == '15.2(4)JB3a' ||
  ver == '15.2(4)JB3b' ||
  ver == '15.2(4)JB3h' ||
  ver == '15.2(4)JB3s' ||
  ver == '15.2(4)JB4' ||
  ver == '15.2(4)JB5' ||
  ver == '15.2(4)JB5h' ||
  ver == '15.2(4)JB5m' ||
  ver == '15.2(4)JB6' ||
  ver == '15.2(4)JN' ||
  ver == '15.2(4)M' ||
  ver == '15.2(4)M1' ||
  ver == '15.2(4)M10' ||
  ver == '15.2(4)M11' ||
  ver == '15.2(4)M2' ||
  ver == '15.2(4)M3' ||
  ver == '15.2(4)M4' ||
  ver == '15.2(4)M5' ||
  ver == '15.2(4)M6' ||
  ver == '15.2(4)M6a' ||
  ver == '15.2(4)M7' ||
  ver == '15.2(4)M8' ||
  ver == '15.2(4)M9' ||
  ver == '15.3(1)SY' ||
  ver == '15.3(1)T' ||
  ver == '15.3(1)T1' ||
  ver == '15.3(1)T2' ||
  ver == '15.3(1)T3' ||
  ver == '15.3(1)T4' ||
  ver == '15.3(2)T' ||
  ver == '15.3(2)T1' ||
  ver == '15.3(2)T2' ||
  ver == '15.3(2)T3' ||
  ver == '15.3(2)T4' ||
  ver == '15.3(3)JA' ||
  ver == '15.3(3)JA1' ||
  ver == '15.3(3)JA10' ||
  ver == '15.3(3)JA1m' ||
  ver == '15.3(3)JA1n' ||
  ver == '15.3(3)JA4' ||
  ver == '15.3(3)JA5' ||
  ver == '15.3(3)JA6' ||
  ver == '15.3(3)JA7' ||
  ver == '15.3(3)JA76' ||
  ver == '15.3(3)JA77' ||
  ver == '15.3(3)JA78' ||
  ver == '15.3(3)JA8' ||
  ver == '15.3(3)JA9' ||
  ver == '15.3(3)JAA' ||
  ver == '15.3(3)JAB' ||
  ver == '15.3(3)JAX' ||
  ver == '15.3(3)JAX1' ||
  ver == '15.3(3)JAX2' ||
  ver == '15.3(3)JB' ||
  ver == '15.3(3)JB75' ||
  ver == '15.3(3)JBB' ||
  ver == '15.3(3)JBB1' ||
  ver == '15.3(3)JBB2' ||
  ver == '15.3(3)JBB4' ||
  ver == '15.3(3)JBB5' ||
  ver == '15.3(3)JBB6' ||
  ver == '15.3(3)JBB8' ||
  ver == '15.3(3)JC' ||
  ver == '15.3(3)JC1' ||
  ver == '15.3(3)JC2' ||
  ver == '15.3(3)JC3' ||
  ver == '15.3(3)JC4' ||
  ver == '15.3(3)JD' ||
  ver == '15.3(3)JN3' ||
  ver == '15.3(3)JN4' ||
  ver == '15.3(3)JN7' ||
  ver == '15.3(3)JN8' ||
  ver == '15.3(3)JN9' ||
  ver == '15.3(3)JNB' ||
  ver == '15.3(3)JNB1' ||
  ver == '15.3(3)JNB2' ||
  ver == '15.3(3)JNB3' ||
  ver == '15.3(3)JNB4' ||
  ver == '15.3(3)JNC' ||
  ver == '15.3(3)JNC1' ||
  ver == '15.3(3)JNC2' ||
  ver == '15.3(3)JNC3' ||
  ver == '15.3(3)JND' ||
  ver == '15.3(3)JNP' ||
  ver == '15.3(3)JNP1' ||
  ver == '15.3(3)JNP2' ||
  ver == '15.3(3)JNP3' ||
  ver == '15.3(3)JPB' ||
  ver == '15.3(3)JPB1' ||
  ver == '15.3(3)JPB2' ||
  ver == '15.3(3)JPC' ||
  ver == '15.3(3)JPC1' ||
  ver == '15.3(3)JPC2' ||
  ver == '15.3(3)M' ||
  ver == '15.3(3)M1' ||
  ver == '15.3(3)M2' ||
  ver == '15.3(3)M3' ||
  ver == '15.3(3)M4' ||
  ver == '15.3(3)M5' ||
  ver == '15.3(3)M6' ||
  ver == '15.3(3)M7' ||
  ver == '15.3(3)M8' ||
  ver == '15.4(1)CG' ||
  ver == '15.4(1)CG1' ||
  ver == '15.4(1)T' ||
  ver == '15.4(1)T1' ||
  ver == '15.4(1)T2' ||
  ver == '15.4(1)T3' ||
  ver == '15.4(1)T4' ||
  ver == '15.4(2)CG' ||
  ver == '15.4(2)T' ||
  ver == '15.4(2)T1' ||
  ver == '15.4(2)T2' ||
  ver == '15.4(2)T3' ||
  ver == '15.4(2)T4' ||
  ver == '15.4(3)M' ||
  ver == '15.4(3)M1' ||
  ver == '15.4(3)M2' ||
  ver == '15.4(3)M3' ||
  ver == '15.4(3)M4' ||
  ver == '15.4(3)M5' ||
  ver == '15.4(3)M6' ||
  ver == '15.4(3)M6a' ||
  ver == '15.5(1)T' ||
  ver == '15.5(1)T1' ||
  ver == '15.5(1)T2' ||
  ver == '15.5(1)T3' ||
  ver == '15.5(1)T4' ||
  ver == '15.5(2)T' ||
  ver == '15.5(2)T1' ||
  ver == '15.5(2)T2' ||
  ver == '15.5(2)T3' ||
  ver == '15.5(2)T4' ||
  ver == '15.5(3)M' ||
  ver == '15.5(3)M0a' ||
  ver == '15.5(3)M1' ||
  ver == '15.5(3)M2' ||
  ver == '15.6(1)T' ||
  ver == '15.6(1)T0a' ||
  ver == '15.6(1)T1' ||
  ver == '15.6(1)T2' ||
  ver == '15.6(2)T' ||
  ver == '15.6(2)T1' ||
  ver == '15.6(3)M' ||
  ver == '15.6(3)M0a'
) flag++;

cmds = make_list();
# Check that device is configured as a DHCP client
if (flag && get_kb_item("Host/local_checks_enabled"))
{
  flag = 0;
  buf = cisco_command_kb_item("Host/Cisco/Config/show running-config | include dhcp", "show running-config | include dhcp");
  if (check_cisco_result(buf))
  {
    if (preg(string:buf, pattern:"ip address dhcp", multiline:TRUE))
    {
      cmds = make_list(cmds, "show running-config | include dhcp");
      # Check if device is configured as a DHCP server or DHCP relay agent
      buf2 =  cisco_command_kb_item("Host/Cisco/Config/show running-config | include helper|(ip dhcp pool)", "show running-config | include helper|(ip dhcp pool)");
      if (check_cisco_result(buf2))
      {
        if (preg(multiline:TRUE, pattern:"ip dhcp pool |ip helper-address [0-9\.]+", string:buf2))
        {
          cmds = make_list(cmds,"show running-config | include helper|(ip dhcp pool)");
          # Check if device is configured to send DHCP Inform/Discover messages
          # If device is configured to send DHCP Inform and Discover messages
          # then not vuln
          buf3 = cisco_command_kb_item("Host/Cisco/Config/show running-config | include (ip dhcp-client network-discovery)", "show running-config | include (ip dhcp-client network-discovery)");
          if (empty(buf3) || check_cisco_result(buf3))
          {
            if (preg(multiline:TRUE, pattern:"ip dhcp-client network-discovery informs .* discovers .*", string:buf3))
            {
              flag = 0;
            }
            else
            {
              flag = 1;
              cmds = make_list(cmds,"show running-config | include (ip dhcp-client network-discovery)");
            }
          }
        }
      }
    }
  }
  else if (cisco_needs_enable(buf))
    override = 1;

  if (!flag && !override) audit(AUDIT_OS_CONF_NOT_VULN, "Cisco IOS", ver);
}

if (flag || override)
{
  security_report_cisco(
    port     : 0,
    severity : SECURITY_HOLE,
    override : override,
    version  : ver,
    bug_id   : "CSCuu43892",
    cmds     : cmds
  );
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");

References