Vulnerabilities > CVE-2019-12646 - Improper Initialization vulnerability in Cisco IOS XE

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
cisco
CWE-665
nessus
NVD
Published: 2019-09-25
Updated: 2023-05-22

Summary

A vulnerability in the Network Address Translation (NAT) Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper processing of transient SIP packets on which NAT is performed on an affected device. An attacker could exploit this vulnerability by using UDP port 5060 to send crafted SIP packets through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

Vulnerable Configurations

Part Description Count
OS
Cisco
13
Hardware
Cisco
12

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
    This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20190925-SIP-ALG.NASL
descriptionAccording to its self-reported version, Cisco IOS XE Software is affected by a denial of service (DoS) vulnerability in the Network Address Translation (NAT) Session Initiation Protocl (SIP) Application Layer Gateway (ALG). This allows an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper processing of transient SIP packets on which NAT is performed on an affected device. An attacker can exploit this vulnerability by using UDP port 5060 to send crafted SIP packets through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a DoS condition. 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 seen2020-05-09
modified2019-10-10
plugin id129780
published2019-10-10
reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/129780
titleCisco IOS XE Software NAT Session Initiation Protocol Application Layer Gateway DoS (cisco-sa-20190925-sip-alg)
code
#TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(129780);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/08");

  script_cve_id("CVE-2019-12646");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn65912");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20190925-sip-alg");
  script_xref(name:"IAVA", value:"2019-A-0352-S");

  script_name(english:"Cisco IOS XE Software NAT Session Initiation Protocol Application Layer Gateway DoS (cisco-sa-20190925-sip-alg)");

  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 denial of service (DoS) vulnerability
in the Network Address Translation (NAT) Session Initiation Protocl (SIP) Application Layer Gateway (ALG). This allows
an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper
processing of transient SIP packets on which NAT is performed on an affected device. An attacker can exploit this
vulnerability by using UDP port 5060 to send crafted SIP packets through an affected device that is performing NAT for
SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a DoS condition.

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-20190925-sip-alg
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?82cd252a");
  script_set_attribute(attribute:"see_also", value:"http://tools.cisco.com/security/center/viewErp.x?alertId=ERP-72547");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn65912");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvn65912");
  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: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-2019-12646");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(399);

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/09/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/10/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:ios_xe");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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('audit.inc');
include('cisco_workarounds.inc');
include('ccf.inc');

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

if (model !~ "^ISR11\d{2}([^0-9]|$)" &&
    model !~ "^ISR4(3|2)\d{2}([^0-9]|$)" &&
    model !~ "^CSR10\d{2}([^0-9]|$)" &&
    model !~ "^ENCS"
   )
  audit(AUDIT_HOST_NOT, 'affected');

version_list=make_list(
  '3.9.2S',
  '3.9.1aS',
  '3.9.1S',
  '3.9.0aS',
  '3.9.0S',
  '3.8.2S',
  '3.8.1S',
  '3.8.0S',
  '3.7.8S',
  '3.7.7S',
  '3.7.6S',
  '3.7.5S',
  '3.7.4aS',
  '3.7.4S',
  '3.7.3S',
  '3.7.2tS',
  '3.7.2S',
  '3.7.1aS',
  '3.7.1S',
  '3.7.0bS',
  '3.7.0S',
  '3.2.0JA',
  '3.18.4S',
  '3.18.3S',
  '3.18.2S',
  '3.18.1S',
  '3.18.0aS',
  '3.18.0S',
  '3.17.4S',
  '3.17.3S',
  '3.17.2S',
  '3.17.1aS',
  '3.17.1S',
  '3.17.0S',
  '3.16.8S',
  '3.16.7bS',
  '3.16.7aS',
  '3.16.7S',
  '3.16.6bS',
  '3.16.6S',
  '3.16.5bS',
  '3.16.5aS',
  '3.16.5S',
  '3.16.4gS',
  '3.16.4eS',
  '3.16.4dS',
  '3.16.4cS',
  '3.16.4bS',
  '3.16.4aS',
  '3.16.4S',
  '3.16.3aS',
  '3.16.3S',
  '3.16.2bS',
  '3.16.2aS',
  '3.16.2S',
  '3.16.1aS',
  '3.16.1S',
  '3.16.0cS',
  '3.16.0bS',
  '3.16.0aS',
  '3.16.0S',
  '3.15.4S',
  '3.15.3S',
  '3.15.2S',
  '3.15.1cS',
  '3.15.1S',
  '3.15.0S',
  '3.14.4S',
  '3.14.3S',
  '3.14.2S',
  '3.14.1S',
  '3.14.0S',
  '3.13.9S',
  '3.13.8S',
  '3.13.7aS',
  '3.13.7S',
  '3.13.6bS',
  '3.13.6aS',
  '3.13.6S',
  '3.13.5aS',
  '3.13.5S',
  '3.13.4S',
  '3.13.3S',
  '3.13.2aS',
  '3.13.2S',
  '3.13.1S',
  '3.13.10S',
  '3.13.0aS',
  '3.13.0S',
  '3.12.4S',
  '3.12.3S',
  '3.12.2S',
  '3.12.1S',
  '3.12.0aS',
  '3.12.0S',
  '3.11.4S',
  '3.11.3S',
  '3.11.2S',
  '3.11.1S',
  '3.11.0S',
  '3.10.9S',
  '3.10.8aS',
  '3.10.8S',
  '3.10.7S',
  '3.10.6S',
  '3.10.5S',
  '3.10.4S',
  '3.10.3S',
  '3.10.2tS',
  '3.10.2aS',
  '3.10.2S',
  '3.10.1S',
  '3.10.10S',
  '3.10.0S',
  '17.6.1',
  '17.5.1',
  '17.4.1',
  '17.3.1',
  '17.2.1',
  '16.9.2s',
  '16.9.2a',
  '16.9.2',
  '16.9.1s',
  '16.9.1d',
  '16.9.1c',
  '16.9.1b',
  '16.9.1a',
  '16.9.1',
  '16.8.2',
  '16.8.1s',
  '16.8.1e',
  '16.8.1d',
  '16.8.1c',
  '16.8.1b',
  '16.8.1a',
  '16.8.1',
  '16.7.4',
  '16.7.3',
  '16.7.2',
  '16.7.1b',
  '16.7.1a',
  '16.7.1',
  '16.6.5b',
  '16.6.5a',
  '16.6.5',
  '16.6.4s',
  '16.6.4a',
  '16.6.4',
  '16.6.3',
  '16.6.2',
  '16.6.1',
  '16.5.3',
  '16.5.2',
  '16.5.1b',
  '16.5.1a',
  '16.5.1',
  '16.4.3',
  '16.4.2',
  '16.4.1',
  '16.3.7',
  '16.3.6',
  '16.3.5b',
  '16.3.5',
  '16.3.4',
  '16.3.3',
  '16.3.2',
  '16.3.1a',
  '16.3.1',
  '16.2.2',
  '16.2.1',
  '16.10.1s',
  '16.10.1g',
  '16.10.1f',
  '16.10.1e',
  '16.10.1d',
  '16.10.1c',
  '16.10.1b',
  '16.10.1a',
  '16.10.1',
  '16.1.3',
  '16.1.2',
  '16.1.1'
);

workarounds = make_list(CISCO_WORKAROUNDS['nat']);
workaround_params = {'sip_agl_disabled' : 1};

reporting = make_array(
  'port'     , 0,
  'severity' , SECURITY_HOLE,
  'version'  , product_info['version'],
  'bug_id'   , 'CSCvn65912',
  '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