Nextcloud Authorization Check Vulnerability - Linux

# SPDX-FileCopyrightText: 2017 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:nextcloud:nextcloud_server";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.106707");
  script_version("2025-02-25T13:24:30+0000");
  script_tag(name:"last_modification", value:"2025-02-25 13:24:30 +0000 (Tue, 25 Feb 2025)");
  script_tag(name:"creation_date", value:"2017-03-30 14:13:45 +0700 (Thu, 30 Mar 2017)");
  script_tag(name:"cvss_base", value:"4.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:S/C:N/I:P/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-10-09 23:20:00 +0000 (Wed, 09 Oct 2019)");

  script_cve_id("CVE-2016-9464");

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

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

  script_name("Nextcloud Authorization Check Vulnerability - Linux");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("Web application abuses");
  script_dependencies("gb_nextcloud_server_http_detect.nasl", "os_detection.nasl");
  script_mandatory_keys("nextcloud/server/detected", "Host/runs_unixoide");

  script_tag(name:"summary", value:"Nextcloud is prone to an improper authorization check vulnerability on
removing shares");

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

  script_tag(name:"insight", value:"The Sharing Backend as implemented in Nextcloud does differentiate between
shares to users and groups. In case of a received group share, users should be able to unshare the file to
themselves but not to the whole group.");

  script_tag(name:"affected", value:"Nextcloud Server prior to 9.0.54");

  script_tag(name:"solution", value:"Update 9.0.54 or later versions.");

  script_xref(name:"URL", value:"https://nextcloud.com/security/advisory/?id=nc-sa-2016-007");

  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: "9.0.54")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "9.0.54");
  security_message(port: port, data: report);
  exit(0);
}

exit(0);