Akka HTTP < 10.2.7 DoS 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.
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# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
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CPE = "cpe:/a:akka:http";

if( description )
{
  script_oid("1.3.6.1.4.1.25623.1.0.147110");
  script_version("2021-11-08T14:03:29+0000");
  script_tag(name:"last_modification", value:"2021-11-08 14:03:29 +0000 (Mon, 08 Nov 2021)");
  script_tag(name:"creation_date", value:"2021-11-05 06:18:41 +0000 (Fri, 05 Nov 2021)");
  script_tag(name:"cvss_base", value:"7.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2018-11-15 17:07:00 +0000 (Thu, 15 Nov 2018)");

  script_cve_id("CVE-2018-16131");

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

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

  script_name("Akka HTTP < 10.2.7 DoS Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("Denial of Service");
  script_dependencies("gb_akka_http_detect.nasl");
  script_mandatory_keys("akka_http/installed");

  script_tag(name:"summary", value:"Akka HTTP is prone to a denial of service (DoS) vulnerability.");

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

  script_tag(name:"insight", value:"The HTTP specification allows arbitrary nesting of comment
  elements in User-Agent and other headers. While parsing a request containing a User-Agent header
  with deeply nested comments, Akka HTTP may fail with a stack overflow in the parser. Stack
  overflows are handled as fatal errors in Akka leading to a complete shutdown of the application.");

  script_tag(name:"impact", value:"An Akka HTTP application server which is exposed to the internet
  can be remotely crashed by sending a crafted User-Agent header leading to a loss of availability.");

  script_tag(name:"affected", value:"Akka HTTP prior to version 10.2.7.");

  script_tag(name:"solution", value:"Update to version 10.2.7 or later.");

  script_xref(name:"URL", value:"https://doc.akka.io/docs/akka-http/current/security/2021-CVE-2021-42697-stack-overflow-parsing-user-agent.html");

  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: "10.2.7")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "10.2.7");
  security_message(port: port, data: report);
  exit(0);
}

exit(99);