Vulnerabilities > CVE-2018-0174 - Improper Input Validation vulnerability in Cisco IOS and IOS XE

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
CWE-20
nessus
NVD
Published: 2018-03-28
Updated: 2024-07-24

Summary

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuh91645.

Vulnerable Configurations

Part Description Count
OS
Cisco
6217
Hardware
Cisco
3
Hardware
Rockwellautomation
6

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyCISCO
    NASL idCISCO-SA-20180328-DHCPR3-IOS.NASL
    descriptionAccording to its self-reported version, the Cisco IOS software running on the remote device is affected by multiple denial of service vulnerabilities in the DHCP client implementation when parsing DHCP packets. An unauthenticated, remote attacker can exploit these issues, via specially crafted DHCP packets, to cause the device to reload.
    last seen2020-06-01
    modified2020-06-02
    plugin id109087
    published2018-04-17
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/109087
    titleCisco IOS DHCP Multiple Vulnerabilities
    code
    #TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(109087);
  script_version("1.6");
  script_cvs_date("Date: 2019/11/08");

  script_cve_id("CVE-2018-0172", "CVE-2018-0173", "CVE-2018-0174");
  script_bugtraq_id(103545, 103552, 103554);
  script_xref(name:"TRA", value:"TRA-2018-06");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvg62730");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvg62754");
  script_xref(name:"CISCO-BUG-ID", value:"CSCuh91645");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20180328-dhcpr1");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20180328-dhcpr2");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20180328-dhcpr3");

  script_name(english:"Cisco IOS DHCP Multiple Vulnerabilities");
  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 multiple denial of service
vulnerabilities in the DHCP client implementation when parsing DHCP
packets. An unauthenticated, remote attacker can exploit these issues,
via specially crafted DHCP packets, to cause the device to reload.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr1
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bfe8b7e0");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr2
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2af6e16d");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr3
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?570bb167");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvg62730");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvg62754");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuh91645");
  script_set_attribute(attribute:"see_also", value:"https://www.tenable.com/security/research/tra-2018-06");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCvg62730, CSCvg62754, and CSCuh91645.");
  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:"2018/03/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/03/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/04/17");

  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) 2018-2019 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(53)SE1' ||
  ver == '12.2(55)SE' ||
  ver == '12.2(46)SE' ||
  ver == '12.2(46)SE2' ||
  ver == '12.2(50)SE2' ||
  ver == '12.2(50)SE1' ||
  ver == '12.2(44)SE2' ||
  ver == '12.2(50)SE5' ||
  ver == '12.2(44)SE1' ||
  ver == '12.2(53)SE' ||
  ver == '12.2(44)SE4' ||
  ver == '12.2(55)SE3' ||
  ver == '12.2(55)SE2' ||
  ver == '12.2(44)SE' ||
  ver == '12.2(52)SE' ||
  ver == '12.2(58)SE' ||
  ver == '12.2(50)SE3' ||
  ver == '12.2(55)SE1' ||
  ver == '12.2(44)SE6' ||
  ver == '12.2(44)SE3' ||
ver == '12.2(53)SE2' ||
ver == '12.2(52)SE1' ||
ver == '12.2(46)SE1' ||
ver == '12.2(54)SE' ||
ver == '12.2(44)SE5' ||
ver == '12.2(50)SE4' ||
ver == '12.2(50)SE' ||
ver == '12.2(58)SE1' ||
ver == '12.2(55)SE4' ||
ver == '12.2(58)SE2' ||
ver == '12.2(55)SE5' ||
ver == '12.2(55)SE6' ||
ver == '12.2(55)SE7' ||
ver == '12.2(55)SE8' ||
ver == '12.2(55)SE9' ||
ver == '12.2(55)SE10' ||
ver == '12.2(55)SE11' ||
ver == '12.2(55)SE12' ||
ver == '12.2(55)SE13' ||
ver == '12.2(44)EX' ||
ver == '12.2(53)EX' ||
ver == '12.2(52)EX' ||
ver == '12.2(44)EX1' ||
ver == '12.2(55)EX' ||
ver == '12.2(46)EX' ||
ver == '12.2(52)EX1' ||
ver == '12.2(55)EX1' ||
ver == '12.2(55)EX2' ||
ver == '12.2(55)EX3' ||
ver == '12.2(58)EX' ||
ver == '12.2(46)EY' ||
ver == '12.2(55)EY' ||
ver == '12.2(52)EY1' ||
ver == '12.2(44)EY' ||
ver == '12.2(52)EY' ||
ver == '12.2(53)EY' ||
ver == '12.2(52)EY2' ||
ver == '12.2(52)EY1b' ||
ver == '12.2(52)EY1c' ||
ver == '12.2(58)EY' ||
ver == '12.2(52)EY3' ||
ver == '12.2(52)EY2a' ||
ver == '12.2(58)EY1' ||
ver == '12.2(52)EY4' ||
ver == '12.2(52)EY3a' ||
ver == '12.2(58)EY2' ||
ver == '12.2(58)EZ' ||
ver == '12.2(53)EZ' ||
ver == '12.2(55)EZ' ||
ver == '12.2(60)EZ' ||
ver == '12.2(60)EZ1' ||
ver == '12.2(60)EZ2' ||
ver == '12.2(60)EZ3' ||
ver == '12.2(60)EZ4' ||
ver == '12.2(60)EZ5' ||
ver == '12.2(60)EZ6' ||
ver == '12.2(60)EZ7' ||
ver == '12.2(60)EZ8' ||
ver == '12.2(60)EZ9' ||
ver == '12.2(60)EZ10' ||
ver == '12.2(60)EZ11' ||
ver == '12.2(60)EZ12' ||
ver == '12.2(50)SG3' ||
ver == '12.2(50)SG6' ||
ver == '12.2(53)SG1' ||
ver == '12.2(46)SG' ||
ver == '12.2(53)SG2' ||
ver == '12.2(50)SG5' ||
ver == '12.2(53)SG3' ||
ver == '12.2(50)SG8' ||
ver == '12.2(50)SG2' ||
ver == '12.2(54)SG1' ||
ver == '12.2(50)SG1' ||
ver == '12.2(52)SG' ||
ver == '12.2(54)SG' ||
ver == '12.2(50)SG' ||
ver == '12.2(50)SG7' ||
ver == '12.2(53)SG4' ||
ver == '12.2(50)SG4' ||
ver == '12.2(46)SG1' ||
ver == '12.2(53)SG5' ||
ver == '12.2(53)SG6' ||
ver == '12.2(53)SG7' ||
ver == '12.2(53)SG8' ||
ver == '12.2(53)SG9' ||
ver == '12.2(53)SG10' ||
ver == '12.2(53)SG11' ||
ver == '12.2(33)SRD7' ||
ver == '12.2(33)SRD6' ||
ver == '12.2(33)SRD2a' ||
ver == '12.2(33)SRD4' ||
ver == '12.2(33)SRD5' ||
ver == '12.2(33)SRD3' ||
ver == '12.2(33)SRD2' ||
ver == '12.2(33)SRD1' ||
ver == '12.2(33)SRD' ||
ver == '12.2(33)SRD8' ||
ver == '12.2(52)XO' ||
ver == '12.2(54)XO' ||
ver == '12.2(50)SQ2' ||
ver == '12.2(50)SQ1' ||
ver == '12.2(50)SQ' ||
ver == '12.2(50)SQ3' ||
ver == '12.2(50)SQ4' ||
ver == '12.2(50)SQ5' ||
ver == '12.2(50)SQ6' ||
ver == '12.2(50)SQ7' ||
ver == '12.2(33)SRE1' ||
ver == '12.2(33)SRE2' ||
ver == '12.2(33)SRE3' ||
ver == '12.2(33)SRE4' ||
ver == '12.2(33)SRE' ||
ver == '12.2(33)SRE0a' ||
ver == '12.2(33)SRE5' ||
ver == '12.2(33)SRE6' ||
ver == '12.2(33)SRE8' ||
ver == '12.2(33)SRE7' ||
ver == '12.2(33)SRE9' ||
ver == '12.2(33)SRE7a' ||
ver == '12.2(33)SRE10' ||
ver == '12.2(33)SRE11' ||
ver == '12.2(33)SRE9a' ||
ver == '12.2(33)SRE12' ||
ver == '12.2(33)SRE13' ||
ver == '12.2(33)SRE14' ||
ver == '12.2(33)SRE15' ||
ver == '12.2(33)SRE15a' ||
ver == '15.0(1)XO1' ||
ver == '15.0(1)XO' ||
ver == '15.0(2)XO' ||
ver == '15.0(1)S2' ||
ver == '15.0(1)S1' ||
ver == '15.0(1)S' ||
ver == '15.0(1)S3a' ||
ver == '15.0(1)S4' ||
ver == '15.0(1)S5' ||
ver == '15.0(1)S4a' ||
ver == '15.0(1)S6' ||
ver == '12.2(33)MRA' ||
ver == '12.2(33)MRB5' ||
ver == '12.2(33)MRB2' ||
ver == '12.2(33)MRB1' ||
ver == '12.2(33)MRB4' ||
ver == '12.2(33)MRB' ||
ver == '12.2(33)MRB3' ||
ver == '12.2(33)MRB6' ||
ver == '15.2(1)S' ||
ver == '15.2(2)S' ||
ver == '15.2(1)S1' ||
ver == '15.2(4)S' ||
ver == '15.2(1)S2' ||
ver == '15.2(2)S1' ||
ver == '15.2(2)S2' ||
ver == '15.2(2)S0a' ||
ver == '15.2(2)S0c' ||
ver == '15.2(4)S1' ||
ver == '15.2(4)S4' ||
ver == '15.2(4)S6' ||
ver == '15.2(4)S2' ||
ver == '15.2(4)S5' ||
ver == '15.2(4)S3' ||
ver == '15.2(4)S3a' ||
ver == '15.2(4)S4a' ||
ver == '15.2(4)S7' ||
ver == '15.0(1)EY' ||
ver == '15.0(1)EY1' ||
ver == '15.0(1)EY2' ||
ver == '15.0(2)EY' ||
ver == '15.0(2)EY1' ||
ver == '15.0(2)EY2' ||
ver == '15.0(2)EY3' ||
ver == '12.2(54)WO' ||
ver == '15.1(2)S' ||
ver == '15.1(1)S' ||
ver == '15.1(1)S1' ||
ver == '15.1(3)S' ||
ver == '15.1(1)S2' ||
ver == '15.1(2)S1' ||
ver == '15.1(2)S2' ||
ver == '15.1(3)S1' ||
ver == '15.1(3)S0a' ||
ver == '15.1(3)S2' ||
ver == '15.1(3)S4' ||
ver == '15.1(3)S3' ||
ver == '15.1(3)S5' ||
ver == '15.1(3)S6' ||
ver == '15.1(3)S5a' ||
ver == '15.0(1)SE' ||
ver == '15.0(2)SE' ||
ver == '15.0(1)SE1' ||
ver == '15.0(1)SE2' ||
ver == '15.0(1)SE3' ||
ver == '15.0(2)SE1' ||
ver == '15.0(2)SE2' ||
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 == '15.0(2)SE10' ||
ver == '15.0(2)SE11' ||
ver == '15.0(2)SE10a' ||
ver == '15.0(2)SE12' ||
ver == '15.1(1)SG' ||
ver == '15.1(2)SG' ||
ver == '15.1(1)SG1' ||
ver == '15.1(1)SG2' ||
ver == '15.1(2)SG1' ||
ver == '15.1(2)SG2' ||
ver == '15.1(2)SG3' ||
ver == '15.1(2)SG4' ||
ver == '15.1(2)SG5' ||
ver == '15.1(2)SG6' ||
ver == '15.1(2)SG7' ||
ver == '15.1(2)SG8' ||
ver == '15.1(2)SG8a' ||
ver == '15.0(1)MR' ||
ver == '15.0(2)MR' ||
ver == '15.0(2)SG' ||
ver == '15.0(2)SG1' ||
ver == '15.0(2)SG2' ||
ver == '15.0(2)SG3' ||
ver == '15.0(2)SG4' ||
ver == '15.0(2)SG5' ||
ver == '15.0(2)SG6' ||
ver == '15.0(2)SG7' ||
ver == '15.0(2)SG8' ||
ver == '15.0(2)SG9' ||
ver == '15.0(2)SG10' ||
ver == '15.0(2)SG11' ||
ver == '15.1(1)MR' ||
ver == '15.1(1)MR1' ||
ver == '15.1(1)MR2' ||
ver == '15.1(1)MR3' ||
ver == '15.1(3)MR' ||
ver == '15.1(1)MR4' ||
ver == '15.0(1)EX' ||
ver == '15.0(2)EX' ||
ver == '15.0(2)EX1' ||
ver == '15.0(2)EX2' ||
ver == '15.0(2)EX3' ||
ver == '15.0(2)EX4' ||
ver == '15.0(2)EX5' ||
ver == '15.0(2)EX8' ||
ver == '15.0(2a)EX5' ||
ver == '15.0(2)EX10' ||
ver == '15.0(2)EX11' ||
ver == '15.0(2)EX13' ||
ver == '15.0(2)EX12' ||
ver == '15.1(2)EY' ||
ver == '15.1(2)EY1a' ||
ver == '15.1(2)EY2' ||
ver == '15.1(2)EY3' ||
ver == '15.1(2)EY2a' ||
ver == '15.1(2)EY4' ||
ver == '15.1(2)SNG' ||
ver == '15.3(1)S' ||
ver == '15.3(2)S' ||
ver == '15.3(3)S' ||
ver == '15.3(1)S2' ||
ver == '15.3(1)S1' ||
ver == '15.3(2)S2' ||
ver == '15.3(2)S1' ||
ver == '15.3(3)S1' ||
ver == '15.3(3)S2' ||
ver == '15.3(3)S3' ||
ver == '15.3(3)S6' ||
ver == '15.3(3)S4' ||
ver == '15.3(3)S1a' ||
ver == '15.3(3)S5' ||
ver == '15.3(3)S7' ||
ver == '15.3(3)S8' ||
ver == '15.3(3)S9' ||
ver == '15.3(3)S10' ||
ver == '15.3(3)S8a' ||
ver == '15.1(2)SNH' ||
ver == '15.1(2)SNI' ||
ver == '15.1(2)SNI1' ||
ver == '15.2(2)SNG' ||
ver == '15.0(2)EC' ||
ver == '15.0(2)EB' ||
ver == '15.2(1)E' ||
ver == '15.2(2)E' ||
ver == '15.2(1)E1' ||
ver == '15.2(3)E' ||
ver == '15.2(1)E2' ||
ver == '15.2(1)E3' ||
ver == '15.2(2)E1' ||
ver == '15.2(4)E' ||
ver == '15.2(3)E1' ||
ver == '15.2(2)E2' ||
ver == '15.2(2a)E1' ||
ver == '15.2(2)E3' ||
ver == '15.2(2a)E2' ||
ver == '15.2(3)E2' ||
ver == '15.2(3a)E' ||
ver == '15.2(3)E3' ||
ver == '15.2(3m)E2' ||
ver == '15.2(4)E1' ||
ver == '15.2(2)E4' ||
ver == '15.2(2)E5' ||
ver == '15.2(4)E2' ||
ver == '15.2(4m)E1' ||
ver == '15.2(3)E4' ||
ver == '15.2(5)E' ||
ver == '15.2(4)E3' ||
ver == '15.2(2)E6' ||
ver == '15.2(5a)E' ||
ver == '15.2(5)E1' ||
ver == '15.2(5b)E' ||
ver == '15.2(4m)E3' ||
ver == '15.2(3m)E8' ||
ver == '15.2(2)E5a' ||
ver == '15.2(5c)E' ||
ver == '15.2(3)E5' ||
ver == '15.2(2)E5b' ||
ver == '15.2(4n)E2' ||
ver == '15.2(4o)E2' ||
ver == '15.2(5a)E1' ||
ver == '15.2(4)E4' ||
ver == '15.2(2)E7' ||
ver == '15.2(5)E2' ||
ver == '15.2(4p)E1' ||
ver == '15.2(6)E' ||
ver == '15.2(5)E2b' ||
ver == '15.2(4)E5' ||
ver == '15.2(5)E2c' ||
ver == '15.2(2)E8' ||
ver == '15.2(4m)E2' ||
ver == '15.2(4o)E3' ||
ver == '15.2(4q)E1' ||
ver == '15.2(6)E0a' ||
ver == '15.2(6)E0b' ||
ver == '15.2(2)E7b' ||
ver == '15.2(4)E5a' ||
ver == '15.2(6)E0c' ||
ver == '15.2(2)E9' ||
ver == '15.1(3)MRA' ||
ver == '15.1(3)MRA1' ||
ver == '15.1(3)MRA2' ||
ver == '15.1(3)MRA3' ||
ver == '15.1(3)MRA4' ||
ver == '15.2(2)SNH1' ||
ver == '15.0(2)ED' ||
ver == '15.0(2)ED1' ||
ver == '15.4(1)S' ||
ver == '15.4(2)S' ||
ver == '15.4(3)S' ||
ver == '15.4(1)S1' ||
ver == '15.4(1)S2' ||
ver == '15.4(2)S1' ||
ver == '15.4(1)S3' ||
ver == '15.4(3)S1' ||
ver == '15.4(2)S2' ||
ver == '15.4(3)S2' ||
ver == '15.4(3)S3' ||
ver == '15.4(1)S4' ||
ver == '15.4(2)S3' ||
ver == '15.4(2)S4' ||
ver == '15.4(3)S4' ||
ver == '15.4(3)S5' ||
ver == '15.4(3)S6' ||
ver == '15.4(3)S7' ||
ver == '15.4(3)S6a' ||
ver == '15.4(3)S8' ||
ver == '15.2(2)SNI' ||
ver == '15.0(2)EZ' ||
ver == '15.2(1)EY' ||
ver == '15.0(2)EJ' ||
ver == '15.0(2)EJ1' ||
ver == '15.0(2)EH' ||
ver == '15.2(5)EX' ||
ver == '15.0(2)EK' ||
ver == '15.0(2)EK1' ||
ver == '15.5(1)S' ||
ver == '15.5(2)S' ||
ver == '15.5(1)S1' ||
ver == '15.5(3)S' ||
ver == '15.5(1)S2' ||
ver == '15.5(1)S3' ||
ver == '15.5(2)S1' ||
ver == '15.5(2)S2' ||
ver == '15.5(3)S1' ||
ver == '15.5(3)S1a' ||
ver == '15.5(2)S3' ||
ver == '15.5(3)S2' ||
ver == '15.5(3)S0a' ||
ver == '15.5(3)S3' ||
ver == '15.5(1)S4' ||
ver == '15.5(2)S4' ||
ver == '15.5(3)S4' ||
ver == '15.5(3)S5' ||
ver == '15.5(3)S6' ||
ver == '15.5(3)S6a' ||
ver == '15.5(3)S6b' ||
ver == '15.1(3)SVG' ||
ver == '15.2(2)EB' ||
ver == '15.2(2)EB1' ||
ver == '15.2(2)EB2' ||
ver == '15.5(3)SN' ||
ver == '15.0(2)SQD' ||
ver == '15.0(2)SQD1' ||
ver == '15.0(2)SQD2' ||
ver == '15.0(2)SQD3' ||
ver == '15.0(2)SQD4' ||
ver == '15.0(2)SQD5' ||
ver == '15.0(2)SQD6' ||
ver == '15.0(2)SQD7' ||
ver == '15.6(1)S' ||
ver == '15.6(2)S' ||
ver == '15.6(2)S1' ||
ver == '15.6(1)S1' ||
ver == '15.6(1)S2' ||
ver == '15.6(2)S0a' ||
ver == '15.6(2)S2' ||
ver == '15.6(1)S3' ||
ver == '15.6(2)S3' ||
ver == '15.6(1)S4' ||
ver == '15.6(2)S4' ||
ver == '15.6(2)SP' ||
ver == '15.6(2)SP1' ||
ver == '15.6(2)SP2' ||
ver == '15.6(2)SP3' ||
ver == '15.6(2)SP3b' ||
ver == '15.6(2)SN' ||
ver == '15.1(3)SVJ2' ||
ver == '15.2(4)EC1' ||
ver == '15.2(4)EC2'
) flag++;

cmds = make_list();
if (flag && get_kb_item("Host/local_checks_enabled"))
{
  flag = 0;
  buf = cisco_command_kb_item("Host/Cisco/Config/show running-config | include ip helper-address", "show running-config | include ip helper-address");
  if (check_cisco_result(buf))
  {
    if (preg(string:buf, pattern:"ip helper-address", multiline:TRUE))
    {
      cmds = make_list(cmds, "show running-config | include ip helper-address");
      buf2 =  cisco_command_kb_item("Host/Cisco/Config/show running-config | include ip dhcp relay information option", "show running-config | include ip dhcp relay information option");
      if (check_cisco_result(buf2))
      {
        if (preg(multiline:TRUE, pattern:"ip dhcp relay information option", string:buf2))
        {
          cmds = make_list(cmds,"show running-config | include ip dhcp relay information option");
          flag = 1;
        }
      }
    }
  }
  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   : "CSCvg62730, CSCvg62754, CSCuh91645",
    cmds     : cmds
  );
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familyCISCO
    NASL idCISCO-SA-20180328-DHCPR3-IOSXE.NASL
    descriptionAccording to its self-reported version, the Cisco IOS software running on the remote device is affected by multiple denial of service vulnerabilities in the DHCP client implementation when parsing DHCP packets. An unauthenticated, remote attacker can exploit these issues, via specially crafted DHCP packets, to cause the device to reload.
    last seen2020-06-01
    modified2020-06-02
    plugin id109088
    published2018-04-17
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/109088
    titleCisco IOS DHCP Multiple Vulnerabilities

References