Informix Server GSKit < 7.0.4.47 / 8.0.50.13 SSL/TLS DoS

#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(72118);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/18");

  script_cve_id("CVE-2013-6329");
  script_bugtraq_id(64249);

  script_name(english:"Informix Server GSKit < 7.0.4.47 / 8.0.50.13 SSL/TLS DoS");
  script_summary(english:"Checks version of Informix Server and GSKit.");

  script_set_attribute(
    attribute:"synopsis",
    value:
"The remote host has an application that is affected by a denial of
service vulnerability."
  );
  script_set_attribute(
    attribute:"description",
    value:
"The remote Informix server ships with a version of IBM's Global
Security kit (GSKit) library that is affected by a denial of service
vulnerability in the SSL/TLS handshake processing code. 

Note that this plugin only checks the version of IBM Informix Server
and GSKit. It does not check for the presence of any workaround."
  );
  # https://www.ibm.com/blogs/psirt/security-bulletin-potential-ssltls-related-denial-of-service-vulnerability-in-ibm-informix-client-sdk-cve-2013-6329/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?da574673");
  script_set_attribute(attribute:"see_also", value:"https://www-304.ibm.com/support/docview.wss?uid=swg21660436");
  script_set_attribute(
    attribute:"solution",
    value:
"Upgrade the Informix server or apply the correct GSKit patch per the
vendor advisory."
  );
  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-2013-6329");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2014/01/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2014/01/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/01/24");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"agent", value:"windows");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:ibm:global_security_kit");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:ibm:informix_dynamic_server");

  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2014-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ibm_gskit_installed.nasl", "ibm_informix_server_installed.nasl");
  script_require_keys("installed_sw/IBM GSKit", "installed_sw/IBM Informix Dynamic Server", "Settings/ParanoidReport");
  exit(0);
}

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

# there is a workaround, but we don't check for it
if (report_paranoia < 2) audit(AUDIT_PARANOID);

ids_app = 'IBM Informix Dynamic Server';
ids_install = get_single_install(app_name:ids_app, exit_if_unknown_ver:TRUE);

ids_ver   = ids_install['version'];
ids_path  = ids_install['path'];

ids_fix   = NULL;
gsk_regex = NULL;
gsk_fix = NULL;

item = pregmatch(pattern: "[cC]([0-9]+)([^0-9]|$)",
                 string: ids_ver);
c_num = 0;
if (!isnull(item) && !isnull(item[1])) c_num = int(item[1]);

# 11.50 <= 11.50.xC9W2 (currently no fix for 11.50 branch)
if (ids_ver =~ "^11\.50($|\.|[^0-9])")
{
  ids_fix     = "None available. Upgrade GSKit.";
  gsk_regex = "^7\.";
  gsk_fix   = "7.0.4.47";
}
# 11.70 < 11.70.xC8
else if (ids_ver =~ "^11\.70($|\.|[^0-9])" && c_num < 8)
{
  ids_fix     = "11.70.xC8";
  gsk_regex = "^8\.0\.50\.";
  gsk_fix   = "8.0.50.13";
}
# 12.10 < 12.10.xC3
else if (ids_ver =~ "^12\.10($|\.|[^0-9])" && c_num < 3)
{
  ids_fix     = "12.10.xC3";
  gsk_regex = "^8\.0\.50\.";
  gsk_fix   = "8.0.50.13";
}
else
  audit(AUDIT_INST_PATH_NOT_VULN, ids_app, ids_ver, ids_path);

# Check GSKit version if Informix is not patched
gsk_app = "IBM GSKit";
gsk_installs = get_installs(app_name:gsk_app);
gsk_report   = NULL;
gsk_vuln     = 0;

foreach gsk_install (gsk_installs[1])
{
  gsk_ver  = gsk_install['version'];
  gsk_path = gsk_install['path'];

  if (gsk_ver =~ gsk_regex &&
      ver_compare(ver:gsk_ver, fix:gsk_fix, strict:FALSE) == -1)
  {
    gsk_report +=
      '\n  Path                    : ' + gsk_path +
      '\n  Installed GSKit version : ' + gsk_ver  +
      '\n  Fixed GSKit version     : ' + gsk_fix  +
      '\n';

    gsk_vuln++;
  }
}

port = get_kb_item("SMB/transport");
if (!port) port = 445;

report =
  '\n' + 'The install of ' + ids_app + ' is vulnerable :' +
  '\n' +
  '\n' + '  Path              : ' + ids_path +
  '\n' + '  Installed version : ' + ids_ver  +
  '\n' + '  Fixed version     : ' + ids_fix  +
  '\n';

server_instances = get_kb_item("Host/" + ids_app + "/Server Instances");
if (!empty_or_null(server_instances))
{
  instance_list = split(server_instances, sep:' / ', keep:FALSE);
  report += '  Server instances  : ' + '\n      - ' + join(instance_list, sep:'\n      - ') + '\n';
}

if (!isnull(gsk_report))
{
  instance = " instance "; is_are   = " is ";

  if (gsk_vuln > 1) {instance = " instances "; is_are = " are ";}

  report +=
    '\nAlso, the following vulnerable'+instance+'of '+gsk_app+is_are+'installed on the'+
    '\nremote host :' +
    '\n' +
    gsk_report;
}

security_report_v4(severity:SECURITY_HOLE, port:port, extra:report);