Vulnerabilities > CVE-2019-12044 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Citrix products

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
citrix
CWE-119
nessus
NVD
Published: 2019-05-22
Updated: 2024-11-21

Summary

A Buffer Overflow exists in Citrix NetScaler Gateway 10.5.x before 10.5.70.x, 11.1.x before 11.1.59.10, 12.0.x before 12.0.59.8, and 12.1.x before 12.1.49.23 and Citrix Application Delivery Controller 10.5.x before 10.5.70.x, 11.1.x before 11.1.59.10, 12.0.x before 12.0.59.8, and 12.1.x before 12.1.49.23.

Vulnerable Configurations

Part Description Count
OS
Citrix
27
Hardware
Citrix
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 familyCGI abuses
NASL idCITRIX_NETSCALER_CTX249976.NASL
descriptionThe remote Citrix ADC or Citrix NetScaler Gateway device is affected by a buffer overflow vulnerability. An attacker may be able to leverage this vulnerability which will result in a denial of service in a specific configuration. Please refer to advisory CTX249976 for more information.
last seen2020-06-01
modified2020-06-02
plugin id125258
published2019-05-17
reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/125258
titleCitrix ADC and Citrix NetScaler Gateway buffer overflow vulnerability (CTX249976)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(125258);
  script_version("1.2");
  script_cvs_date("Date: 2019/10/30 13:24:46");

  script_cve_id("CVE-2019-12044");

  script_name(english:"Citrix ADC and Citrix NetScaler Gateway buffer overflow vulnerability (CTX249976)");
  script_summary(english:"Checks the Citrix NetScaler version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is affected by a buffer overflow vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote Citrix ADC or Citrix NetScaler Gateway device is affected by a buffer overflow vulnerability.
An attacker may be able to leverage this vulnerability which will result in a 
denial of service in a specific configuration.
Please refer to advisory CTX249976 for more information.");

  # https://support.citrix.com/article/CTX249976
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7d161693");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Citrix NetScaler Gateway version 11.1 build 59.10 / 12.0 build 59.8 / 12.1 build 49.23
or refer to vendor documentation for configuration mitigation.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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: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-2019-12044");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");


  script_set_attribute(attribute:"vuln_publication_date", value:"2019/05/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/17");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:citrix:netscaler_access_gateway_firmware");
  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CGI abuses");

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

  script_dependencies("citrix_netscaler_detect.nbin");
  script_require_keys("Host/NetScaler/Detected", "Settings/ParanoidReport");

  exit(0);
}

include('audit.inc');
include('global_settings.inc');
include('misc_func.inc');

# Multiple models are not affected and a mitigation strategy is provided
if (report_paranoia < 2) audit(AUDIT_PARANOID);

app_name = 'Citrix NetScaler';
version = get_kb_item_or_exit('Host/NetScaler/Version');
build = get_kb_item('Host/NetScaler/Build');
enhanced = get_kb_item('Host/NetScaler/Enhanced');
fixed_build = NULL;

if (isnull(build)) exit(0, 'The build number of ' + app_name + ' ' + version + ' could not be determined.');

display_version = version + '-' + build;
version = version + '.' + build;

if (!enhanced)
{
  if (version =~ '^10\\.5' && ver_compare(ver:build, fix:'70.0') < 0)
  {
    fixed_build = 'Apply the configuration mitigation as per advisory or upgrade to a fixed version';
  }
  else if (version =~ '^11\\.1' && ver_compare(ver:build, fix:'59.10') < 0)
  {
    fixed_build = '59.10';
  }
  else if (version =~ '^12\\.0' && ver_compare(ver:build, fix:'59.8') < 0)
  {
    fixed_build = '59.8';
  }
  else if (version =~ '^12\\.1' && ver_compare(ver:build, fix:'49.23') < 0)
  {
    fixed_build = '49.23';
  }
}

if (isnull(fixed_build))
{
  audit(AUDIT_INST_VER_NOT_VULN, app_name, display_version);
}

report =
   '\n  Installed version : ' + display_version +
   '\n  Installed build   : ' + build +
   '\n  Fixed build       : ' + fixed_build +
   '\n';

security_report_v4(port:0, severity:SECURITY_WARNING, extra:report, xss: TRUE);

References