Leafnode denials of service

# SPDX-FileCopyrightText: 2003 Michel Arboi
# 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("1.3.6.1.4.1.25623.1.0.11517");
  script_version("2023-08-01T13:29:10+0000");
  script_tag(name:"last_modification", value:"2023-08-01 13:29:10 +0000 (Tue, 01 Aug 2023)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_cve_id("CVE-2002-1661");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/6490");
  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("Leafnode denials of service");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2003 Michel Arboi");
  script_family("General");
  script_dependencies("nntpserver_detect.nasl");
  script_require_ports("Services/nntp", 119);
  script_mandatory_keys("nntp/detected");

  script_tag(name:"solution", value:"Update to version 1.9.48 or later.");

  script_tag(name:"summary", value:"According to its version number in the banner
  the Leafnode NNTP server is vulnerable to a denial of service.");

  script_tag(name:"impact", value:"The service may:

  - go into an infinite loop with 100% CPU use when an article that has been crossposted to
  several groups, one of which is the prefix of another, and when this article is then requested
  by its Message-ID.

  - hang without consuming CPU while waiting for data that never come.");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"remote_banner");

  exit(0);
}

include("nntp_func.inc");
include("misc_func.inc");
include("port_service_func.inc");

port = nntp_get_port(default:119);

banner = get_kb_item("nntp/banner/" + port);
if(!banner || "Leafnode" >!< banner)
  exit(0);

# Example of banner:
# 200 Leafnode NNTP Daemon, version 1.9.32.rel running at localhost (my fqdn: www.example.com)

if(ereg(string:banner, pattern:"version +1\.9\.2[0-9]") ||
   ereg(string:banner, pattern:"version +1\.9\.([3-9]|[1-3][0-9]|4[0-7])[^0-9]") ||
   ereg(string:banner, pattern:"version +1\.9\.19")) {
  security_message(port:port);
  exit(0);
}

exit(99);