Dropbear Symlink Local File Read Vulnerability (CVE-2017-9079)

# SPDX-FileCopyrightText: 2017 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:dropbear_ssh_project:dropbear_ssh";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.108172");
  script_version("2025-09-02T05:39:48+0000");
  script_tag(name:"last_modification", value:"2025-09-02 05:39:48 +0000 (Tue, 02 Sep 2025)");
  script_tag(name:"creation_date", value:"2017-06-06 08:24:50 +0200 (Tue, 06 Jun 2017)");
  script_tag(name:"cvss_base", value:"4.7");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:M/Au:N/C:C/I:N/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-10-04 09:15:00 +0000 (Fri, 04 Oct 2019)");

  script_cve_id("CVE-2017-9079");

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

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

  script_name("Dropbear Symlink Local File Read Vulnerability (CVE-2017-9079)");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("General");
  script_dependencies("gb_dropbear_consolidation.nasl");
  script_mandatory_keys("dropbear_ssh/detected");

  script_tag(name:"summary", value:"Dropbear is prone to a local file read vulnerability via
  symlinks.");

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

  script_tag(name:"insight", value:"The flaw exists because ~/.ssh/authorized_keys is read with root
  privileges and symlinks are followed.");

  script_tag(name:"impact", value:"Successfully exploiting this issue might allow local users to
  read certain files as root, if the file has the authorized_keys file format with a
  command= option.");

  script_tag(name:"affected", value:"Dropbear versions prior to 2017.75.");

  script_tag(name:"solution", value:"Update to version 2017.75 or later.");

  script_xref(name:"URL", value:"https://lists.ucc.gu.uwa.edu.au/pipermail/dropbear/2017q2/001985.html");
  script_xref(name:"URL", value:"https://matt.ucc.asn.au/dropbear/CHANGES");

  exit(0);
}

include("version_func.inc");
include("host_details.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 ) )
  exit( 0 );

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

if( version_is_less( version:vers, test_version:"2017.75" ) ) {
  report = report_fixed_ver( installed_version:vers, fixed_version:"2017.75", install_path:path );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );