Exim < 4.92.2 RCE Vulnerability

# SPDX-FileCopyrightText: 2019 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-only

CPE = "cpe:/a:exim:exim";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.142854");
  script_version("2024-01-10T05:05:17+0000");
  script_tag(name:"last_modification", value:"2024-01-10 05:05:17 +0000 (Wed, 10 Jan 2024)");
  script_tag(name:"creation_date", value:"2019-09-06 03:34:05 +0000 (Fri, 06 Sep 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:3.0/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:"2020-08-24 17:37:00 +0000 (Mon, 24 Aug 2020)");

  script_cve_id("CVE-2019-15846");

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

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

  script_name("Exim < 4.92.2 RCE Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2019 Greenbone AG");
  script_family("General");
  script_dependencies("gb_exim_smtp_detect.nasl");
  script_mandatory_keys("exim/detected");

  script_tag(name:"summary", value:"Exim is prone to a 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:"The vulnerability is exploitable by sending a SNI ending in a
  backslash-null sequence during the initial TLS handshake. The exploit exists as a POC.

  For more details see doc/doc-txt/cve-2019-15846/ in the source code repository of Exim.");

  script_tag(name:"impact", value:"A local or remote attacker can execute programs with root
  privileges.");

  script_tag(name:"affected", value:"Exim version 4.92.1 and prior.");

  script_tag(name:"solution", value:"Update to version 4.92.2 or later.");

  script_xref(name:"URL", value:"https://exim.org/static/doc/security/CVE-2019-15846.txt");
  script_xref(name:"URL", value:"https://www.openwall.com/lists/oss-security/2019/09/04/1");

  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: "4.92.1")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "4.92.2");
  security_message(port: port, data: report);
  exit(0);
}

exit(99);