Vulnerabilities > CVE-2018-0315 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Cisco IOS XE 16.7.1/16.8.1

047910
CVSS 9.8 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
cisco
CWE-119
critical
nessus
NVD
Published: 2018-06-07
Updated: 2024-11-21

Summary

A vulnerability in the authentication, authorization, and accounting (AAA) security services of Cisco IOS XE Software could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device or cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect memory operations that the affected software performs when the software parses a username during login authentication. An attacker could exploit this vulnerability by attempting to authenticate to an affected device. A successful exploit could allow the attacker to execute arbitrary code on the affected device or cause the affected device to reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are running Cisco IOS XE Software Release Fuji 16.7.1 or Fuji 16.8.1 and are configured to use AAA for login authentication. Cisco Bug IDs: CSCvi25380.

Vulnerable Configurations

Part Description Count
OS
Cisco
2

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.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20180606-AAA.NASL
descriptionAccording to its self-reported version, Cisco IOS XE Software is affected by a remote code execution vulnerability in the authentication, authorization, and accounting (AAA) security services due to incorrect memory operations that the affected software performs when the software parses a username during login authentication. An unauthenticated, remote attacker can exploit this, by attempting to authenticate to an affected device, in order to execute arbitrary code or cause the device to reload and stop responding. Please see the included Cisco BIDs and Cisco Security Advisory for more information. Note that Nessus has not tested for this issue but has instead relied only on the application
last seen2020-06-01
modified2020-06-02
plugin id131703
published2019-12-04
reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/131703
titleCisco IOS XE Software Authentication, Authorization, and Accounting Login Authentication RCE (cisco-sa-20180606-aaa)
code
#TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(131703);
  script_version("1.4");
  script_cvs_date("Date: 2020/01/16");

  script_cve_id("CVE-2018-0315");
  script_bugtraq_id(104410);
  script_xref(name:"CISCO-BUG-ID", value:"CSCvi25380");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20180606-aaa");

  script_name(english:"Cisco IOS XE Software Authentication, Authorization, and Accounting Login Authentication RCE (cisco-sa-20180606-aaa)");

  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, Cisco IOS XE Software is affected by a remote code execution vulnerability in
the authentication, authorization, and accounting (AAA) security services due to incorrect memory operations that the
affected software performs when the software parses a username during login authentication. An unauthenticated, remote
attacker can exploit this, by attempting to authenticate to an affected device, in order to execute arbitrary code or
cause the device to reload and stop responding.

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180606-aaa
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?47fc6762");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvi25380");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID(s) CSCvi25380.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  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:U/C:H/I:H/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-2018-0315");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/06/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/12/04");

  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) 2019-2020 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('cisco_workarounds.inc');
include('ccf.inc');

product_info = cisco::get_product_info(name:'Cisco IOS XE Software');

version_list = make_list(
  '16.7.1',
  '16.7.1a',
  '16.7.1b',
  '16.8.1',
  '16.8.1a',
  '16.8.1b'
);

workarounds = make_list(CISCO_WORKAROUNDS['aaa_authentication_login']);
workaround_params = make_list();

reporting = make_array(
  'port'     , 0,
  'severity' , SECURITY_HOLE,
  'version'  , product_info['version'],
  'bug_id'   , 'CSCvi25380',
  'cmds'     , make_list('show running-config')
);

cisco::check_and_report(
  product_info:product_info,
  workarounds:workarounds,
  workaround_params:workaround_params,
  reporting:reporting,
  vuln_versions:version_list
);

References