vsftpd < 2.3.3 DoS Vulnerability

# SPDX-FileCopyrightText: 2011 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

CPE = "cpe:/a:vsftpd_project:vsftpd";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.103101");
  script_version("2026-02-19T05:56:52+0000");
  script_tag(name:"last_modification", value:"2026-02-19 05:56:52 +0000 (Thu, 19 Feb 2026)");
  script_tag(name:"creation_date", value:"2011-03-03 13:33:12 +0100 (Thu, 03 Mar 2011)");
  script_tag(name:"cvss_base", value:"4.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:S/C:N/I:N/A:P");

  script_cve_id("CVE-2011-0762");

  script_tag(name:"qod_type", value:"remote_banner_unreliable");

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

  script_name("vsftpd < 2.3.3 DoS Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2011 Greenbone AG");
  script_family("FTP");
  script_dependencies("sw_vsftpd_detect.nasl");
  script_mandatory_keys("vsftpd/detected");

  script_tag(name:"summary", value:"vsftpd FTP server is prone to a denial of service (DoS)
  vulnerability.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");

  script_tag(name:"impact", value:"Successfully exploiting allows remote attackers to crash the
  affected application, denying service to legitimate users.");

  script_tag(name:"affected", value:"vsftpd version 2.3.2 and prior.");

  # nb:
  # - The text prior to "At this point: v2.3.3 released!" from the Changelog is relevant here...
  # - The securityfocus.com link mentions 2.3.2 and 2.3 as affected and lists 2.3.4 as not
  #   vulnerable but the fix is already included in 2.3.3 like shown on the mentioned Changelog
  script_tag(name:"solution", value:"Update to version 2.3.3 or later.");

  script_xref(name:"URL", value:"https://web.archive.org/web/20210121211832/http://www.securityfocus.com/bid/46617");
  script_xref(name:"URL", value:"https://security.appspot.com/vsftpd/Changelog.txt");

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if( ! port = get_app_port( cpe:CPE ) )
  exit( 0 );

if( ! version = get_app_version( cpe:CPE, port:port ) )
  exit( 0 );

if( version_in_range( version:version, test_version:"2.0", test_version2:"2.3.2" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"2.3.3" );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );