Open-FTPD Authentication Bypass 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("1.3.6.1.4.1.25623.1.0.801228");
  script_version("2023-07-28T16:09:07+0000");
  script_tag(name:"last_modification", value:"2023-07-28 16:09:07 +0000 (Fri, 28 Jul 2023)");
  script_tag(name:"creation_date", value:"2010-07-16 18:57:03 +0200 (Fri, 16 Jul 2010)");
  script_cve_id("CVE-2010-2620");
  script_tag(name:"cvss_base", value:"9.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_name("Open-FTPD Authentication Bypass Vulnerability");
  script_xref(name:"URL", value:"http://www.exploit-db.com/exploits/13932");
  script_xref(name:"URL", value:"http://secunia.com/advisories/40284");

  script_tag(name:"qod_type", value:"remote_vul");
  script_category(ACT_ATTACK);
  script_copyright("Copyright (C) 2010 Greenbone AG");
  script_family("FTP");
  script_dependencies("ftpserver_detect_type_nd_version.nasl");
  script_require_ports("Services/ftp", 21);
  script_mandatory_keys("ftp/open-ftpd/detected");

  script_tag(name:"impact", value:"Successful exploitation will allow attackers to bypass certain
  security restrictions and execute FTP commands without any authentication.");

  script_tag(name:"affected", value:"Open&Compact FTP Server (Open-FTPD) Version 1.2 and prior.");

  script_tag(name:"insight", value:"The flaw is due to access not being restricted to various FTP
  commands before a user is properly authenticated. This can be exploited to execute FTP commands
  without any authentication.");

  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:"summary", value:"Open&Compact FTP Server (Open-FTPD) is prone to an authentication bypass vulnerability.");

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

  exit(0);
}

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

port = ftp_get_port(default:21);
banner = ftp_get_banner(port:port);
if(!banner || "Gabriel's FTP Server" >!< banner) {
  exit(0);
}

soc = open_sock_tcp(port);
if(!soc){
  exit(0);
}

ftp_send_cmd(socket:soc, cmd:"LIST");
result = ftp_recv_listing(socket:soc);
close(soc);

if("226 Transfer Complete" >< result)
{
  security_message(port:port);
  exit(0);
}