Apache HTTP Server 2.4.49 - 2.4.50 Directory Traversal / RCE Vulnerability - Linux

# 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:apache:http_server";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.117710");
  script_version("2022-08-09T10:11:17+0000");
  script_tag(name:"last_modification", value:"2022-08-09 10:11:17 +0000 (Tue, 09 Aug 2022)");
  script_tag(name:"creation_date", value:"2021-10-08 05:36:04 +0000 (Fri, 08 Oct 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:"2021-10-15 21:15:00 +0000 (Fri, 15 Oct 2021)");

  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-2021-42013");

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

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

  script_name("Apache HTTP Server 2.4.49 - 2.4.50 Directory Traversal / RCE Vulnerability - Linux");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("Web Servers");
  script_dependencies("gb_apache_http_server_consolidation.nasl", "os_detection.nasl");
  script_mandatory_keys("apache/http_server/detected", "Host/runs_unixoide");

  script_tag(name:"summary", value:"Apache HTTP Server is prone to a directory traversal
  and a possible remote code execution (RCE) vulnerability.");

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

  script_tag(name:"insight", value:"It was found that the fix for CVE-2021-41773 in Apache HTTP
  Server 2.4.50 was insufficient. An attacker could use a path traversal attack to map URLs to files
  outside the directories configured by Alias-like directives.

  If files outside of these directories are not protected by the usual default configuration
  'require all denied', these requests can succeed. If CGI scripts are also enabled for these
  aliased paths, this could allow for remote code execution.");

  script_tag(name:"affected", value:"Apache HTTP Server version 2.4.49 through 2.4.50.");

  script_tag(name:"solution", value:"Update to version 2.4.51 or later.");

  script_xref(name:"URL", value:"https://httpd.apache.org/security/vulnerabilities_24.html");

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

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

if (!infos = get_app_version_and_location(cpe: CPE, port: port, exit_no_version: TRUE, version_regex: "^[0-9]+\.[0-9]+\.[0-9]+"))
  exit(0);

version = infos["version"];
location = infos["location"];

if (version_in_range(version: version, test_version: "2.4.49", test_version2: "2.4.50")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "2.4.51", install_path: location);
  security_message(port: port, data: report);
  exit(0);
}

exit(99);