CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
77.3%
Nextcloud Server is prone to a vulnerability in the brute-force
protection.
# SPDX-FileCopyrightText: 2021 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-or-later
CPE = "cpe:/a:nextcloud:nextcloud_server";
if (description)
{
script_oid("1.3.6.1.4.1.25623.1.0.146119");
script_version("2023-05-15T09:08:55+0000");
script_tag(name:"last_modification", value:"2023-05-15 09:08:55 +0000 (Mon, 15 May 2023)");
script_tag(name:"creation_date", value:"2021-06-15 01:54:29 +0000 (Tue, 15 Jun 2021)");
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:H/I:H/A:H");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2021-07-09 09:15:00 +0000 (Fri, 09 Jul 2021)");
script_cve_id("CVE-2021-22915");
script_tag(name:"qod_type", value:"remote_banner_unreliable");
script_tag(name:"solution_type", value:"VendorFix");
script_name("Nextcloud Server Brute-Force Protection Vulnerability (NC-SA-2021-009)");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2021 Greenbone AG");
script_family("Web application abuses");
script_dependencies("gb_nextcloud_detect.nasl");
script_mandatory_keys("nextcloud/installed");
script_tag(name:"summary", value:"Nextcloud Server is prone to a vulnerability in the brute-force
protection.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");
script_tag(name:"insight", value:"Nextcloud server is vulnerable to brute force attacks due to
lack of inclusion of IPv6 subnets in rate-limiting considerations. This could potentially result
in an attacker bypassing rate-limit controls such as the Nextcloud brute-force protection.");
script_tag(name:"affected", value:"Nextcloud server prior to versions 19.0.11, 20.x through
20.0.9 and 21.x through 21.0.1.");
script_tag(name:"solution", value:"Update to version 19.0.11, 20.0.10, 21.0.2 or later.");
script_xref(name:"URL", value:"https://nextcloud.com/security/advisory/?id=NC-SA-2021-009");
exit(0);
}
include("host_details.inc");
include("version_func.inc");
if (!port = get_app_port(cpe: CPE))
exit(0);
if (!infos = get_app_version_and_location(cpe: CPE, port: port, exit_no_version: TRUE))
exit(0);
version = infos["version"];
location = infos["location"];
if (version_is_less(version: version, test_version: "19.0.11")) {
report = report_fixed_ver(installed_version: version, fixed_version: "19.0.11", install_path: location);
security_message(port: port, data: report);
exit(0);
}
if (version_in_range(version: version, test_version: "20.0.0", test_version2: "20.0.9")) {
report = report_fixed_ver(installed_version: version, fixed_version: "20.0.10", install_path: location);
security_message(port: port, data: report);
exit(0);
}
if (version_in_range(version: version, test_version: "21.0.0", test_version2: "21.0.1")) {
report = report_fixed_ver(installed_version: version, fixed_version: "21.0.2", install_path: location);
security_message(port: port, data: report);
exit(0);
}
exit(99);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
77.3%