Vulnerabilities > CVE-2019-1965 - Missing Release of Resource after Effective Lifetime vulnerability in Cisco Nx-Os

047910
CVSS 4.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
network
low complexity
cisco
CWE-772
nessus
NVD
Published: 2019-08-28
Updated: 2020-10-16

Summary

A vulnerability in the Virtual Shell (VSH) session management for Cisco NX-OS Software could allow an authenticated, remote attacker to cause a VSH process to fail to delete upon termination. This can lead to a build-up of VSH processes that overtime can deplete system memory. When there is no system memory available, this can cause unexpected system behaviors and crashes. The vulnerability is due to the VSH process not being properly deleted when a remote management connection to the device is disconnected. An attacker could exploit this vulnerability by repeatedly performing a remote management connection to the device and terminating the connection in an unexpected manner. A successful exploit could allow the attacker to cause the VSH processes to fail to delete, which can lead to a system-wide denial of service (DoS) condition. The attacker must have valid user credentials to log in to the device using the remote management connection.

Vulnerable Configurations

Part Description Count
OS
Cisco
510
Hardware
Cisco
86

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • HTTP DoS
    An attacker performs flooding at the HTTP level to bring down only a particular web application rather than anything listening on a TCP/IP connection. This denial of service attack requires substantially fewer packets to be sent which makes DoS harder to detect. This is an equivalent of SYN flood in HTTP. The idea is to keep the HTTP session alive indefinitely and then repeat that hundreds of times. This attack targets resource depletion weaknesses in web server software. The web server will wait to attacker's responses on the initiated HTTP sessions while the connection threads are being exhausted.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20190828-NXOS-MEMLEAK-DOS.NASL
descriptionAccording to its self-reported version, Cisco NX-OS Software is affected by vulnerability in the Virtual Shell (VSH) session management which could allow an authenticated, remote attacker to cause a VSH process to fail to delete upon termination. This can lead to a build-up of VSH processes that overtime can deplete system memory. When there is no system memory available, this can cause unexpected system behaviors and crashes. The vulnerability is due to the VSH process not being properly deleted when a remote management connection to the device is disconnected. An attacker could exploit this vulnerability by repeatedly performing a remote management connection to the device and terminating the connection in an unexpected manner. A successful exploit could allow the attacker to cause the VSH processes to fail to delete, which can lead to a system-wide denial of service (DoS) condition. The attacker must have valid user credentials to log in to the device using the remote management connection. Please see the included Cisco BIDs and Cisco Security Advisory for more information
last seen2020-06-01
modified2020-06-02
plugin id128547
published2019-09-06
reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/128547
titleCisco NX-OS Software Remote Management Memory Leak Denial of Service Vulnerability (CVE-2019-1965)
code
#TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(128547);
  script_version("1.5");
  script_cvs_date("Date: 2019/12/20");

  script_cve_id("CVE-2019-1965");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvi15409");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn50393");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn50443");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn50446");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn52167");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20190828-nxos-memleak-dos");
  script_xref(name:"IAVA", value:"2019-A-0317");

  script_name(english:"Cisco NX-OS Software Remote Management Memory Leak Denial of Service Vulnerability (CVE-2019-1965)");
  script_summary(english:"Checks the version of Cisco NX-OS Software");

  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 NX-OS Software is affected by vulnerability in the Virtual Shell (VSH)
session management which could allow an authenticated, remote attacker to cause a VSH process to fail to delete upon
termination. This can lead to a build-up of VSH processes that overtime can deplete system memory. When there is no
system memory available, this can cause unexpected system behaviors and crashes. The vulnerability is due to the VSH
process not being properly deleted when a remote management connection to the device is disconnected. An attacker
could exploit this vulnerability by repeatedly performing a remote management connection to the device and terminating
the connection in an unexpected manner. A successful exploit could allow the attacker to cause the VSH processes to
fail to delete, which can lead to a system-wide denial of service (DoS) condition. The attacker must have valid user
credentials to log in to the device using the remote management connection.

Please see the included Cisco BIDs and Cisco Security Advisory for more information");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nxos-memleak-dos
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?169b4cec");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvi15409");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn50393");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn50443");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn50446");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn52167");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCvi15409, CSCvn50393, CSCvn50443, CSCvn50446,
and CSCvn52167");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/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:L/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:"cvss_score_source", value:"CVE-2019-1965");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(400);

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/08/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/09/06");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os");
  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 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_nxos_version.nasl");
  script_require_keys("Host/Cisco/NX-OS/Version", "Host/Cisco/NX-OS/Model", "Host/Cisco/NX-OS/Device");

  exit(0);
}

include('audit.inc');
include('cisco_workarounds.inc');
include('ccf.inc');

product_info = cisco::get_product_info(name:'Cisco NX-OS Software');

cbi = '';

if ('MDS' >< product_info.device && product_info.model =~ '^90[0-9][0-9]')
  cbi = 'CSCvn50393';
if ('UCS' >< product_info.device && product_info.model =~ '^(6[23])[0-9][0-9]')
  cbi = 'CSCvn52167';
else if ('Nexus' >< product_info.device)
{
  if (product_info.model =~ '^(3[056]|90)[0-9][0-9]')
    cbi = 'CSCvi15409';
  else if (product_info.model =~ '^(5[56]|60)[0-9][0-9]')
    cbi = 'CSCvn50446';
  else if (product_info.model =~ '^(7[07])[0-9][0-9]')
    cbi = 'CSCvn50443';
  else audit(AUDIT_HOST_NOT, 'affected');
}
else audit(AUDIT_HOST_NOT, 'affected');

version_list=make_list(
  '5.0(4b)',
  '5.0(4c)',
  '5.0(4d)',
  '5.0(7)',
  '5.0(8)',
  '5.0(8a)',
  '5.2(1)',
  '5.2(3a)',
  '5.2(4)',
  '5.2(5)',
  '5.2(7)',
  '5.2(9)',
  '5.2(3)',
  '5.2(9a)',
  '5.2(2s)',
  '5.2(6)',
  '5.2(6b)',
  '5.2(8)',
  '5.2(8a)',
  '5.2(6a)',
  '5.2(8b)',
  '5.2(8c)',
  '5.2(8d)',
  '5.2(8e)',
  '5.2(8f)',
  '5.2(8g)',
  '5.2(8h)',
  '5.2(8i)',
  '6.1(1)',
  '6.1(2)',
  '6.1(3)',
  '6.1(4)',
  '6.1(4a)',
  '6.1(5)',
  '5.0(2)N2(1a)',
  '5.0(3)A1(1)',
  '5.0(3)A1(2)',
  '5.0(3)A1(2a)',
  '5.0(3)N1(1c)',
  '5.0(3)N1(1)',
  '5.0(3)N1(1a)',
  '5.0(3)N1(1b)',
  '5.0(3)N2(1)',
  '5.0(3)N2(2)',
  '5.0(3)N2(2a)',
  '5.0(3)N2(2b)',
  '5.0(3)U1(1)',
  '5.0(3)U1(1a)',
  '5.0(3)U1(1b)',
  '5.0(3)U1(2)',
  '5.0(3)U1(2a)',
  '5.0(3)U1(1c)',
  '5.0(3)U2(1)',
  '5.0(3)U2(2)',
  '5.0(3)U2(2c)',
  '5.0(3)U2(2d)',
  '5.0(3)U3(1)',
  '5.0(3)U3(2)',
  '5.0(3)U3(2a)',
  '5.0(3)U4(1)',
  '5.0(3)U5(1)',
  '5.0(3)U5(1a)',
  '5.0(3)U5(1b)',
  '5.0(3)U5(1c)',
  '5.0(3)U5(1d)',
  '5.0(3)U5(1e)',
  '5.0(3)U5(1f)',
  '5.0(3)U5(1g)',
  '5.0(3)U5(1h)',
  '5.0(3)U5(1i)',
  '5.0(3)U5(1j)',
  '5.1(3)N1(1)',
  '5.1(3)N1(1a)',
  '5.1(3)N2(1)',
  '5.1(3)N2(1a)',
  '5.1(3)N2(1b)',
  '5.1(3)N2(1c)',
  '5.2(1)N1(1)',
  '5.2(1)N1(1a)',
  '5.2(1)N1(1b)',
  '5.2(1)N1(2)',
  '5.2(1)N1(2a)',
  '5.2(1)N1(3)',
  '5.2(1)N1(4)',
  '5.2(1)N1(5)',
  '5.2(1)N1(6)',
  '5.2(1)N1(7)',
  '5.2(1)N1(8a)',
  '5.2(1)N1(8)',
  '5.2(1)N1(8b)',
  '5.2(1)N1(9)',
  '5.2(1)N1(9a)',
  '5.2(1)N1(9b)',
  '6.0(1)',
  '6.0(2)',
  '6.0(3)',
  '6.0(4)',
  '6.0(2)A1(1)',
  '6.0(2)A1(1a)',
  '6.0(2)A1(1b)',
  '6.0(2)A1(1c)',
  '6.0(2)A1(1d)',
  '6.0(2)A1(1e)',
  '6.0(2)A1(1f)',
  '6.0(2)A1(2d)',
  '6.0(2)A3(1)',
  '6.0(2)A3(2)',
  '6.0(2)A3(4)',
  '6.0(2)A4(1)',
  '6.0(2)A4(2)',
  '6.0(2)A4(3)',
  '6.0(2)A4(4)',
  '6.0(2)A4(5)',
  '6.0(2)A4(6)',
  '6.0(2)A6(1a)',
  '6.0(2)A6(2a)',
  '6.0(2)A6(3a)',
  '6.0(2)A6(4a)',
  '6.0(2)A6(5a)',
  '6.0(2)A6(5b)',
  '6.0(2)A6(6)',
  '6.0(2)A6(7)',
  '6.0(2)A6(8)',
  '6.0(2)A7(1a)',
  '6.0(2)A7(2)',
  '6.0(2)A7(2a)',
  '6.0(2)A8(2)',
  '6.0(2)A8(3)',
  '6.0(2)A8(4a)',
  '6.0(2)A8(5)',
  '6.0(2)A8(6)',
  '6.0(2)A8(7)',
  '6.0(2)A8(7a)',
  '6.0(2)A8(7b)',
  '6.0(2)A8(8)',
  '6.0(2)A8(9)',
  '6.0(2)A8(10a)',
  '6.0(2)A8(10)',
  '6.0(2)N1(1)',
  '6.0(2)N1(2)',
  '6.0(2)N1(2a)',
  '6.0(2)N1(1a)',
  '6.0(2)N2(1)',
  '6.0(2)N2(1b)',
  '6.0(2)N2(2)',
  '6.0(2)N2(3)',
  '6.0(2)N2(4)',
  '6.0(2)N2(5)',
  '6.0(2)N2(5a)',
  '6.0(2)N2(6)',
  '6.0(2)N2(7)',
  '6.0(2)N2(5b)',
  '6.0(2)U1(1)',
  '6.0(2)U1(2)',
  '6.0(2)U1(1a)',
  '6.0(2)U1(3)',
  '6.0(2)U1(4)',
  '6.0(2)U2(1)',
  '6.0(2)U2(2)',
  '6.0(2)U2(3)',
  '6.0(2)U2(4)',
  '6.0(2)U2(5)',
  '6.0(2)U2(6)',
  '6.0(2)U3(1)',
  '6.0(2)U3(2)',
  '6.0(2)U3(3)',
  '6.0(2)U3(4)',
  '6.0(2)U3(5)',
  '6.0(2)U3(6)',
  '6.0(2)U3(7)',
  '6.0(2)U3(8)',
  '6.0(2)U3(9)',
  '6.0(2)U4(1)',
  '6.0(2)U4(2)',
  '6.0(2)U4(3)',
  '6.0(2)U4(4)',
  '6.0(2)U5(1)',
  '6.0(2)U5(2)',
  '6.0(2)U5(3)',
  '6.0(2)U5(4)',
  '6.0(2)U6(6)',
  '6.0(2)U6(7)',
  '6.0(2)U6(8)',
  '6.0(2)U6(5a)',
  '6.0(2)U6(5b)',
  '6.0(2)U6(5c)',
  '6.0(2)U6(9)',
  '6.0(2)U6(10)',
  '6.1(2)I1(3)',
  '6.1(2)I1(2)',
  '6.1(2)I2(1)',
  '6.1(2)I2(2)',
  '6.1(2)I2(2a)',
  '6.1(2)I2(3)',
  '6.1(2)I2(2b)',
  '6.1(2)I3(1)',
  '6.1(2)I3(2)',
  '6.1(2)I3(3)',
  '6.1(2)I3(4)',
  '6.1(2)I3(3a)',
  '6.1(2)I3(4a)',
  '6.1(2)I3(4b)',
  '6.1(2)I3(4c)',
  '6.1(2)I3(4d)',
  '6.1(2)I3(4e)',
  '6.1(2)I3(5)',
  '6.1(2)I3(5b)',
  '6.2(2)',
  '6.2(2a)',
  '6.2(6)',
  '6.2(6b)',
  '6.2(8)',
  '6.2(8a)',
  '6.2(8b)',
  '6.2(10)',
  '6.2(12)',
  '6.2(18)',
  '6.2(16)',
  '6.2(14b)',
  '6.2(14)',
  '6.2(14a)',
  '6.2(6a)',
  '6.2(20)',
  '6.2(1)',
  '6.2(3)',
  '6.2(5)',
  '6.2(5a)',
  '6.2(5b)',
  '6.2(7)',
  '6.2(9)',
  '6.2(9a)',
  '6.2(9b)',
  '6.2(9c)',
  '6.2(11)',
  '6.2(11b)',
  '6.2(11c)',
  '6.2(11d)',
  '6.2(11e)',
  '6.2(13)',
  '6.2(13a)',
  '6.2(13b)',
  '6.2(15)',
  '6.2(17)',
  '6.2(19)',
  '6.2(21)',
  '6.2(23)',
  '6.2(20a)',
  '6.2(25)',
  '6.2(17a)',
  '7.0(0)N1(1)',
  '7.0(1)N1(1)',
  '7.0(2)N1(1)',
  '7.0(3)F1(1)',
  '7.0(3)F2(1)',
  '7.0(3)F2(2)',
  '7.0(3)F3(1)',
  '7.0(3)F3(2)',
  '7.0(3)F3(3)',
  '7.0(3)F3(3a)',
  '7.0(3)F3(4)',
  '7.0(3)F3(3c)',
  '7.0(3)F3(5)',
  '7.0(3)I1(1)',
  '7.0(3)I1(1a)',
  '7.0(3)I1(1b)',
  '7.0(3)I1(2)',
  '7.0(3)I1(3)',
  '7.0(3)I1(3a)',
  '7.0(3)I1(3b)',
  '7.0(3)I1(1z)',
  '7.0(3)I2(2a)',
  '7.0(3)I2(2b)',
  '7.0(3)I2(2c)',
  '7.0(3)I2(2d)',
  '7.0(3)I2(2e)',
  '7.0(3)I2(3)',
  '7.0(3)I2(4)',
  '7.0(3)I2(5)',
  '7.0(3)I2(1a)',
  '7.0(3)I2(2)',
  '7.0(3)I2(2r)',
  '7.0(3)I2(2s)',
  '7.0(3)I2(2v)',
  '7.0(3)I2(2w)',
  '7.0(3)I2(2x)',
  '7.0(3)I2(2y)',
  '7.0(3)I3(1)',
  '7.0(3)I4(1)',
  '7.0(3)I4(2)',
  '7.0(3)I4(3)',
  '7.0(3)I4(4)',
  '7.0(3)I4(5)',
  '7.0(3)I4(6)',
  '7.0(3)I4(7)',
  '7.0(3)I4(8)',
  '7.0(3)I4(8a)',
  '7.0(3)I4(8b)',
  '7.0(3)I4(1t)',
  '7.0(3)I4(6t)',
  '7.0(3)I5(1)',
  '7.0(3)I5(2)',
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  '7.0(3)I5(3a)',
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  '7.0(3)I6(1)',
  '7.0(3)I6(2)',
  '7.0(3)I7(1)',
  '7.0(3)I7(2)',
  '7.0(3)I7(3)',
  '7.0(3)I7(3z)',
  '7.0(3)IX1(2)',
  '7.0(3)IX1(2a)',
  '7.0(3)N1(1)',
  '7.0(4)N1(1)',
  '7.0(4)N1(1a)',
  '7.0(5)N1(1)',
  '7.0(5)N1(1a)',
  '7.0(6)N1(1)',
  '7.0(6)N1(4s)',
  '7.0(6)N1(3s)',
  '7.0(6)N1(2s)',
  '7.0(7)N1(1)',
  '7.0(7)N1(1b)',
  '7.0(7)N1(1a)',
  '7.0(8)N1(1)',
  '7.0(8)N1(1a)',
  '7.1(0)N1(1a)',
  '7.1(0)N1(1b)',
  '7.1(0)N1(1)',
  '7.1(1)N1(1)',
  '7.1(1)N1(1a)',
  '7.1(2)N1(1)',
  '7.1(2)N1(1a)',
  '7.1(3)N1(1)',
  '7.1(3)N1(2)',
  '7.1(3)N1(5)',
  '7.1(3)N1(4)',
  '7.1(3)N1(3)',
  '7.1(3)N1(2a)',
  '7.1(4)N1(1)',
  '7.1(4)N1(1d)',
  '7.1(4)N1(1c)',
  '7.1(4)N1(1a)',
  '7.1(5)N1(1)',
  '7.2(0)D1(1)',
  '7.2(0)N1(1)',
  '7.2(1)D1(1)',
  '7.2(1)N1(1)',
  '7.2(2)D1(2)',
  '7.2(2)D1(1)',
  '7.2(2)D1(3)',
  '7.2(2)D1(4)',
  '7.3(0)D1(1)',
  '7.3(0)DX(1)',
  '7.3(0)DY(1)',
  '7.3(0)N1(1)',
  '7.3(0)N1(1b)',
  '7.3(0)N1(1a)',
  '7.3(1)D1(1)',
  '7.3(1)DY(1)',
  '7.3(1)N1(1)',
  '7.3(2)D1(1)',
  '7.3(2)D1(2)',
  '7.3(2)D1(3)',
  '7.3(2)D1(3a)',
  '7.3(2)N1(1)',
  '7.3(2)N1(1b)',
  '7.3(2)N1(1c)',
  '7.3(3)N1(1)',
  '8.0(1)',
  '8.1(1)',
  '8.1(2)',
  '8.1(2a)',
  '8.1(1a)',
  '8.1(1b)',
  '8.2(1)',
  '8.2(2)',
  '8.3(1)',
  '8.3(2)',
  '7.3(4)N1(1)',
  '7.3(4)N1(1a)',
  '7.3(3)D1(1)',
  '7.0(3)IA7(1)',
  '7.0(3)IA7(2)',
  '7.0(3)IC4(4)',
  '7.0(3)IM3(1)',
  '7.0(3)IM3(2)',
  '7.0(3)IM3(2a)',
  '7.0(3)IM3(2b)',
  '7.0(3)IM3(3)',
  '7.0(3)IM7(2)'
);

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

reporting = make_array(
  'port'     , 0,
  'severity' , SECURITY_WARNING,
  'version'  , product_info['version'],
  'bug_id'   , cbi
);

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

References