Concrete5 < 8.3.0 Authentication Bypass Vulnerability

# SPDX-FileCopyrightText: 2018 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:concretecms:concrete_cms";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.140817");
  script_version("2025-10-22T05:39:59+0000");
  script_tag(name:"last_modification", value:"2025-10-22 05:39:59 +0000 (Wed, 22 Oct 2025)");
  script_tag(name:"creation_date", value:"2018-02-27 13:37:17 +0700 (Tue, 27 Feb 2018)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2021-11-01 14:43:00 +0000 (Mon, 01 Nov 2021)");

  script_cve_id("CVE-2017-18195");

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

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

  script_name("Concrete5 < 8.3.0 Authentication Bypass Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2018 Greenbone AG");
  script_family("Web application abuses");
  script_dependencies("gb_portlandlabs_concrete_cms_http_detect.nasl");
  script_mandatory_keys("concrete_cms/detected");

  script_tag(name:"summary", value:"An issue was discovered in tools/conversations/view_ajax.php in
  Concrete5. An unauthenticated user can enumerate comments from all blog posts by POSTing requests
  to /index.php/tools/required/conversations/view_ajax with incremental 'cnvID' integers.");

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

  script_tag(name:"affected", value:"Concrete5 prior to version 8.3.0.");

  script_tag(name:"solution", value:"Update to version 8.3.0 or later.");

  script_xref(name:"URL", value:"https://github.com/concrete5/concrete5/releases/tag/8.3.0");
  script_xref(name:"URL", value:"https://github.com/r3naissance/NSE/blob/master/http-vuln-cve2017-18195.nse");

  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_is_less(version: version, test_version: "8.3.0")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "8.3.0");
  security_message(port: port, data: report);
  exit(0);
}

exit(99);