Samba Server Symlink Race Information Disclosure Vulnerability

# 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:samba:samba";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.810729");
  script_version("2023-07-14T16:09:27+0000");
  script_cve_id("CVE-2017-2619");
  script_tag(name:"cvss_base", value:"6.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_tag(name:"last_modification", value:"2023-07-14 16:09:27 +0000 (Fri, 14 Jul 2023)");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2022-08-29 20:20:00 +0000 (Mon, 29 Aug 2022)");
  script_tag(name:"creation_date", value:"2017-04-04 11:09:27 +0530 (Tue, 04 Apr 2017)");
  script_name("Samba Server Symlink Race Information Disclosure Vulnerability");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("General");
  script_dependencies("smb_nativelanman.nasl", "gb_samba_detect.nasl");
  script_mandatory_keys("samba/smb_or_ssh/detected");

  script_xref(name:"URL", value:"https://www.exploit-db.com/exploits/41740/");
  script_xref(name:"URL", value:"https://bugs.chromium.org/p/project-zero/issues/detail?id=1039");
  script_xref(name:"URL", value:"https://www.samba.org/samba/security/CVE-2017-2619.html");

  script_tag(name:"summary", value:"Samba is prone to an information disclosure vulnerability.");

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

  script_tag(name:"insight", value:"The time-of-check, time-of-use race
  condition in Samba, a SMB/CIFS file, print, and login server for Unix.
  A malicious client can take advantage of this flaw by exploiting a symlink
  race to access areas of the server file system not exported under a share
  definition.");

  script_tag(name:"impact", value:"Successful exploitation will allow clients
  to access non-exported parts of the file system via symlinks.");

  script_tag(name:"affected", value:"Samba Server versions 4.6.x before 4.6.1,

  Samba Server versions 4.4.x before 4.4.12, and

  Samba Server versions 4.5.x before 4.5.7.");

  script_tag(name:"solution", value:"Upgrade to Samba 4.6.1 or 4.4.12 or 4.5.7 or later.");

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

  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'];
loc = infos['location'];

if(version_is_equal( version:vers, test_version:"4.6.0" )){
  fix = "4.6.1";
  VULN = TRUE ;
}
else if( version_in_range( version:vers, test_version:"4.4.0", test_version2:"4.4.11" )){
  fix = "4.4.11";
  VULN = TRUE ;
}
else if( version_in_range( version:vers, test_version:"4.5.0", test_version2:"4.5.6" )){
  fix = "4.5.7";
  VULN = TRUE ;
}

if( VULN ){
  report = report_fixed_ver( installed_version:vers, fixed_version:fix, install_path:loc );
  security_message( data:report, port:port );
  exit( 0 );
}

exit( 99 );