Cisco ASA Content Security and Control Security Services Module (CSC-SSM) DoS (cisco-sa-20160309-csc)

2016-03-21T00:00:00
ID CISCO-SA-20160309-CSC.NASL
Type nessus
Reporter Tenable
Modified 2018-08-09T00:00:00

Description

The remote Cisco Adaptive Security Appliance (ASA) is missing a vendor-supplied security patch. It is, therefore, affected by a denial of service vulnerability in the Content Security and Control Security Services Module (CSC-SSM) due to improper handling of HTTPS packets. An unauthenticated, remote attacker can exploit this, by sending a high rate of HTTPS packets, to exhaust available memory resources, resulting in a denial of service condition.

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

include("compat.inc");

if (description)
{
  script_id(90066);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2018/08/09");

  script_cve_id("CVE-2016-1312");
  script_bugtraq_id(84281);
  script_xref(name:"CISCO-BUG-ID", value:"CSCue76147");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20160309-csc");

  script_name(english:"Cisco ASA Content Security and Control Security Services Module (CSC-SSM) DoS (cisco-sa-20160309-csc)");
  script_summary(english:"Checks the ASA version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The remote Cisco Adaptive Security Appliance (ASA) is missing a
vendor-supplied security patch. It is, therefore, affected by a denial
of service vulnerability in the Content Security and Control Security
Services Module (CSC-SSM) due to improper handling of HTTPS packets.
An unauthenticated, remote attacker can exploit this, by sending a 
high rate of HTTPS packets, to exhaust available memory resources,
resulting in a denial of service condition.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160309-csc
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?884fa710");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCue76147.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A: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_attribute(attribute:"vuln_publication_date", value:"2016/03/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/03/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/03/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:adaptive_security_appliance_software");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CISCO");

  script_copyright(english:"This script is Copyright (C) 2016-2018 Tenable Network Security, Inc.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/Cisco/ASA", "Host/Cisco/ASA/model", "Host/local_checks_enabled");

  exit(0);
}

include("audit.inc");
include("cisco_func.inc");
include("cisco_kb_cmd_func.inc");

get_kb_item_or_exit("Host/local_checks_enabled");

model = get_kb_item_or_exit('Host/Cisco/ASA/model');
if (model !~ '^55[0-9]{2}($|[^0-9])')
  audit(AUDIT_HOST_NOT, "Cisco ASA 5500");

buf = cisco_command_kb_item("Host/Cisco/Config/show_module",
                            "show module");
override = FALSE;
csc_ver = NULL;

if (check_cisco_result(buf))
{
  if (!ereg(multiline:TRUE, pattern:"CSC SSM", string:buf))
    exit(0, "CSC SSM Module not detected.");

  extract = pregmatch(multiline:TRUE, pattern:"^.*CSC SSM\s+(Up|Down)\s+([0-9\.]+).*$", string:buf);
  if (!empty_or_null(extract))
    csc_ver = extract[2];
  else
    exit(1, "Unable to obtain CSC SSM Module version.");
}
else if (cisco_needs_enable(buf))
  override = TRUE;

fix = "6.6.1164.0";

if (empty_or_null(csc_ver))
  audit(AUDIT_UNKNOWN_APP_VER, "Cisco ASA " + model);

if (csc_ver =~ "^6\.6\." &&
    ver_compare(ver:csc_ver, fix:fix, strict:FALSE) < 0 &&
    csc_ver !~ "^6\.6\.1157\.")
{
  security_report_cisco(
    port     : 0,
    severity : SECURITY_HOLE,
    override : override,
    version  : csc_ver,
    fix      : fix,
    bug_id   : "CSCue76147",
    cmds     : make_list("show module")
  );
  exit(0);
}
else
  audit(AUDIT_INST_VER_NOT_VULN, "Cisco ASA " + model + ", CSC SSM", csc_ver);