Vulnerabilities > CVE-2016-1823 - Out-of-bounds Read vulnerability in Apple products

047910
CVSS 7.8 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
local
low complexity
apple
CWE-125
nessus
exploit available

Summary

The IOHIDDevice::handleReportWithTime function in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (out-of-bounds read and memory corruption) via a crafted IOHIDReportType enum, which triggers an incorrect cast, a different vulnerability than CVE-2016-1824.

Vulnerable Configurations

Part Description Count
OS
Apple
300

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Overread Buffers
    An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.

Exploit-Db

descriptionOS X Kernel - OOB Read of Object Pointer Due to Insufficient Checks in Raw Cast to enum Type. CVE-2016-1823. Dos exploit for osx platform
fileexploits/osx/dos/39927.c
idEDB-ID:39927
last seen2016-06-11
modified2016-06-10
platformosx
port
published2016-06-10
reporterGoogle Security Research
sourcehttps://www.exploit-db.com/download/39927/
titleOS X Kernel - OOB Read of Object Pointer Due to Insufficient Checks in Raw Cast to enum Type
typedos

Nessus

  • NASL familyMacOS X Local Security Checks
    NASL idMACOSX_10_11_5.NASL
    descriptionThe remote host is running a version of Mac OS X that is 10.11.x prior to 10.11.5. It is, therefore, affected by multiple vulnerabilities in the following components : - AMD - apache_mod_php - AppleGraphicsControl - AppleGraphicsPowerManagement - Assistant - ATS - Audio - Captive - CFNetwork - CommonCrypto - CoreCapture - CoreStorage - Crash - Disk - Disk - Driver - Drivers - Drivers - Graphics - Graphics - Graphics - ImageIO - Images - Intel - IOAcceleratorFamily - IOAudioFamily - IOFireWireFamily - IOHIDFamily - Kernel - libc - libxml2 - libxslt - Lock - MapKit - Messages - Multi-Touch - Network - NVIDIA - OpenGL - Proxies - QuickTime - Reporter - SceneKit - Screen - Tcl - Utility Note that successful exploitation of the most serious issues can result in arbitrary code execution.
    last seen2020-06-01
    modified2020-06-02
    plugin id91228
    published2016-05-19
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/91228
    titleMac OS X 10.11.x < 10.11.5 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(91228);
      script_version("1.10");
      script_cvs_date("Date: 2019/11/19");
    
      script_cve_id(
        "CVE-2016-1792",
        "CVE-2016-1793",
        "CVE-2016-1794",
        "CVE-2016-1795",
        "CVE-2016-1796",
        "CVE-2016-1797",
        "CVE-2016-1798",
        "CVE-2016-1799",
        "CVE-2016-1801",
        "CVE-2016-1802",
        "CVE-2016-1803",
        "CVE-2016-1804",
        "CVE-2016-1805",
        "CVE-2016-1806",
        "CVE-2016-1807",
        "CVE-2016-1808",
        "CVE-2016-1809",
        "CVE-2016-1810",
        "CVE-2016-1811",
        "CVE-2016-1812",
        "CVE-2016-1813",
        "CVE-2016-1814",
        "CVE-2016-1815",
        "CVE-2016-1816",
        "CVE-2016-1817",
        "CVE-2016-1818",
        "CVE-2016-1819",
        "CVE-2016-1820",
        "CVE-2016-1821",
        "CVE-2016-1822",
        "CVE-2016-1823",
        "CVE-2016-1824",
        "CVE-2016-1825",
        "CVE-2016-1826",
        "CVE-2016-1827",
        "CVE-2016-1828",
        "CVE-2016-1829",
        "CVE-2016-1830",
        "CVE-2016-1831",
        "CVE-2016-1832",
        "CVE-2016-1833",
        "CVE-2016-1834",
        "CVE-2016-1835",
        "CVE-2016-1836",
        "CVE-2016-1837",
        "CVE-2016-1838",
        "CVE-2016-1839",
        "CVE-2016-1840",
        "CVE-2016-1842",
        "CVE-2016-1843",
        "CVE-2016-1844",
        "CVE-2016-1846",
        "CVE-2016-1848",
        "CVE-2016-1850",
        "CVE-2016-1851",
        "CVE-2016-1853",
        "CVE-2016-1861",
        "CVE-2016-3141",
        "CVE-2016-3142",
        "CVE-2016-4070",
        "CVE-2016-4071",
        "CVE-2016-4072",
        "CVE-2016-4073",
        "CVE-2016-4650"
      );
      script_bugtraq_id(
        84271,
        84306,
        85800,
        85801,
        85991,
        85993,
        90692,
        90694,
        90696,
        90697,
        90698,
        90801,
        91353,
        92034
      );
      script_xref(name:"APPLE-SA", value:"APPLE-SA-2016-05-16-4");
    
      script_name(english:"Mac OS X 10.11.x < 10.11.5 Multiple Vulnerabilities");
      script_summary(english:"Checks the version of Mac OS X.");
    
      script_set_attribute(attribute:"synopsis", value:
    "The remote Mac OS X host is affected by multiple vulnerabilities.");
      script_set_attribute(attribute:"description", value:
    "The remote host is running a version of Mac OS X that is 10.11.x prior
    to 10.11.5. It is, therefore, affected by multiple vulnerabilities in
    the following components :
    
      - AMD
      - apache_mod_php
      - AppleGraphicsControl
      - AppleGraphicsPowerManagement
      - Assistant
      - ATS
      - Audio
      - Captive
      - CFNetwork
      - CommonCrypto
      - CoreCapture
      - CoreStorage
      - Crash
      - Disk
      - Disk
      - Driver
      - Drivers
      - Drivers
      - Graphics
      - Graphics
      - Graphics
      - ImageIO
      - Images
      - Intel
      - IOAcceleratorFamily
      - IOAudioFamily
      - IOFireWireFamily
      - IOHIDFamily
      - Kernel
      - libc
      - libxml2
      - libxslt
      - Lock
      - MapKit
      - Messages
      - Multi-Touch
      - Network
      - NVIDIA
      - OpenGL
      - Proxies
      - QuickTime
      - Reporter
      - SceneKit
      - Screen
      - Tcl
      - Utility
    
    Note that successful exploitation of the most serious issues can
    result in arbitrary code execution.");
      script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT206567");
      # http://lists.apple.com/archives/security-announce/2016/May/msg00004.html
      script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?46de3fda");
      script_set_attribute(attribute:"solution", value:
    "Upgrade to Mac OS X version 10.11.5 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-4650");
    
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2016/05/16");
      script_set_attribute(attribute:"patch_publication_date", value:"2016/05/16");
      script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/19");
    
      script_set_attribute(attribute:"plugin_type", value:"combined");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:apple:mac_os_x");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"MacOS X Local Security Checks");
    
      script_copyright(english:"This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
    
      script_dependencies("ssh_get_info.nasl", "os_fingerprint.nasl");
      script_require_ports("Host/MacOSX/Version", "Host/OS");
    
      exit(0);
    }
    
    include("audit.inc");
    include("global_settings.inc");
    include("misc_func.inc");
    
    os = get_kb_item("Host/MacOSX/Version");
    if (!os)
    {
      os = get_kb_item_or_exit("Host/OS");
      if ("Mac OS X" >!< os)
        audit(AUDIT_OS_NOT, "Mac OS X");
    
      c = get_kb_item("Host/OS/Confidence");
      if (c <= 70)
        exit(1, "Cannot determine the host's OS with sufficient confidence.");
    }
    if (!os)
      audit(AUDIT_OS_NOT, "Mac OS X");
    
    match = eregmatch(pattern:"Mac OS X ([0-9]+(\.[0-9]+)+)", string:os);
    if (isnull(match)) exit(1, "Failed to parse the Mac OS X version ('" + os + "').");
    
    version = match[1];
    
    if (
      version !~ "^10\.11([^0-9]|$)"
    ) audit(AUDIT_OS_NOT, "Mac OS X 10.11 or later", "Mac OS X "+version);
    
    fix = "10.11.5";
    if (ver_compare(ver:version, fix:fix, strict:FALSE) == -1)
    {
      items = make_array("Installed version", version,
                         "Fixed version", fix
                        );
      order = make_list("Installed version", "Fixed version");
      report = report_items_str(report_items:items, ordered_fields:order);
    
      security_report_v4(port:0, extra:report, severity:SECURITY_HOLE);
      exit(0);
    
     }
    else
      audit(AUDIT_INST_VER_NOT_VULN, "Mac OS X", version);
    
  • NASL familyMacOS X Local Security Checks
    NASL idMACOS_10_12_2.NASL
    descriptionThe remote host is running a version of macOS that is 10.12.x prior to 10.12.2. It is, therefore, affected by multiple vulnerabilities in the following components : - apache_mod_php - AppleGraphicsPowerManagement - Assets - Audio - Bluetooth - CoreCapture - CoreFoundation - CoreGraphics - CoreMedia External Displays - CoreMedia Playback - CoreStorage - CoreText - curl - Directory Services - Disk Images - FontParser - Foundation - Grapher - ICU - ImageIO - Intel Graphics Driver - IOFireWireFamily - IOAcceleratorFamily - IOHIDFamily - IOKit - IOSurface - Kernel - kext tools - libarchive - LibreSSL - OpenLDAP - OpenPAM - OpenSSL - Power Management - Security - syslog - WiFi - xar Note that successful exploitation of the most serious issues can result in arbitrary code execution. Furthermore, CVE-2016-6304, CVE-2016-7596, and CVE-2016-7604 also affect Mac OS X versions 10.10.5 and 10.11.6. However, this plugin does not check those versions.
    last seen2020-06-01
    modified2020-06-02
    plugin id95917
    published2016-12-16
    reporterThis script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/95917
    titlemacOS 10.12.x < 10.12.2 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(95917);
      script_version("1.9");
      script_cvs_date("Date: 2020/01/07");
    
      script_cve_id(
        "CVE-2016-1777",
        "CVE-2016-1823",
        "CVE-2016-4688",
        "CVE-2016-4691",
        "CVE-2016-4693",
        "CVE-2016-5419",
        "CVE-2016-5420",
        "CVE-2016-5421",
        "CVE-2016-6303",
        "CVE-2016-6304",
        "CVE-2016-7141",
        "CVE-2016-7167",
        "CVE-2016-7411",
        "CVE-2016-7412",
        "CVE-2016-7413",
        "CVE-2016-7414",
        "CVE-2016-7416",
        "CVE-2016-7417",
        "CVE-2016-7418",
        "CVE-2016-7588",
        "CVE-2016-7591",
        "CVE-2016-7594",
        "CVE-2016-7595",
        "CVE-2016-7596",
        "CVE-2016-7600",
        "CVE-2016-7602",
        "CVE-2016-7603",
        "CVE-2016-7604",
        "CVE-2016-7605",
        "CVE-2016-7606",
        "CVE-2016-7607",
        "CVE-2016-7608",
        "CVE-2016-7609",
        "CVE-2016-7612",
        "CVE-2016-7615",
        "CVE-2016-7616",
        "CVE-2016-7617",
        "CVE-2016-7618",
        "CVE-2016-7619",
        "CVE-2016-7620",
        "CVE-2016-7621",
        "CVE-2016-7622",
        "CVE-2016-7624",
        "CVE-2016-7625",
        "CVE-2016-7627",
        "CVE-2016-7628",
        "CVE-2016-7629",
        "CVE-2016-7633",
        "CVE-2016-7636",
        "CVE-2016-7637",
        "CVE-2016-7643",
        "CVE-2016-7644",
        "CVE-2016-7655",
        "CVE-2016-7657",
        "CVE-2016-7658",
        "CVE-2016-7659",
        "CVE-2016-7660",
        "CVE-2016-7661",
        "CVE-2016-7662",
        "CVE-2016-7663",
        "CVE-2016-7714",
        "CVE-2016-7742",
        "CVE-2016-7761",
        "CVE-2016-8615",
        "CVE-2016-8616",
        "CVE-2016-8617",
        "CVE-2016-8618",
        "CVE-2016-8619",
        "CVE-2016-8620",
        "CVE-2016-8621",
        "CVE-2016-8622",
        "CVE-2016-8623",
        "CVE-2016-8624",
        "CVE-2016-8625"
      );
      script_bugtraq_id(
        85054,
        90698,
        92292,
        92306,
        92309,
        92754,
        92975,
        92984,
        93004,
        93005,
        93006,
        93007,
        93008,
        93009,
        93011,
        93150,
        94094,
        94096,
        94097,
        94098,
        94100,
        94101,
        94102,
        94103,
        94105,
        94106,
        94107,
        94572,
        94903,
        94904,
        94905,
        94906
      );
      script_xref(name:"APPLE-SA", value:"APPLE-SA-2016-12-13-1");
    
      script_name(english:"macOS 10.12.x < 10.12.2 Multiple Vulnerabilities");
      script_summary(english:"Checks the version of macOS.");
    
      script_set_attribute(attribute:"synopsis", value:
    "The remote host is missing a macOS update that fixes multiple security
    vulnerabilities.");
      script_set_attribute(attribute:"description", value:
    "The remote host is running a version of macOS that is 10.12.x prior to
    10.12.2. It is, therefore, affected by multiple vulnerabilities in the
    following components :
    
      - apache_mod_php
      - AppleGraphicsPowerManagement
      - Assets
      - Audio
      - Bluetooth
      - CoreCapture
      - CoreFoundation
      - CoreGraphics
      - CoreMedia External Displays
      - CoreMedia Playback
      - CoreStorage
      - CoreText
      - curl
      - Directory Services
      - Disk Images
      - FontParser
      - Foundation
      - Grapher
      - ICU
      - ImageIO
      - Intel Graphics Driver
      - IOFireWireFamily
      - IOAcceleratorFamily
      - IOHIDFamily
      - IOKit
      - IOSurface
      - Kernel
      - kext tools
      - libarchive
      - LibreSSL
      - OpenLDAP
      - OpenPAM
      - OpenSSL
      - Power Management
      - Security
      - syslog
      - WiFi
      - xar
    
    Note that successful exploitation of the most serious issues can
    result in arbitrary code execution.
    
    Furthermore, CVE-2016-6304, CVE-2016-7596, and CVE-2016-7604 also
    affect Mac OS X versions 10.10.5 and 10.11.6. However, this plugin
    does not check those versions.");
      script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT207423");
      # http://lists.apple.com/archives/security-announce/2016/Dec/msg00003.html
      script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?38dabd46");
      script_set_attribute(attribute:"solution", value:
    "Upgrade to macOS version 10.12.2 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-7644");
    
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
      script_set_attribute(attribute:"exploited_by_malware", value:"true");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2016/03/21");
      script_set_attribute(attribute:"patch_publication_date", value:"2016/12/13");
      script_set_attribute(attribute:"plugin_publication_date", value:"2016/12/16");
    
      script_set_attribute(attribute:"plugin_type", value:"combined");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:apple:macos");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"MacOS X Local Security Checks");
    
      script_copyright(english:"This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
    
      script_dependencies("ssh_get_info.nasl", "os_fingerprint.nasl");
      script_require_ports("Host/MacOSX/Version", "Host/OS");
    
      exit(0);
    }
    
    include("vcf.inc");
    include("vcf_extras_apple.inc");
    
    app_info = vcf::apple::get_macos_info();
    
    vcf::apple::check_macos_restrictions(restrictions:['10.12']);
    
    constraints = [{ "fixed_version" : "10.12.2" }];
    
    vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);
    
  • NASL familyMisc.
    NASL idAPPLETV_9_2_1.NASL
    descriptionAccording to its banner, the version of the remote Apple TV device is prior to 9.2.1. It is, therefore, affected by multiple vulnerabilities in the following components : - CFNetwork Proxies - CommonCrypto - CoreCapture - Disk Images - ImageIO - IOAcceleratorFamily - IOHIDFamily - Kernel - libc - libxml2 - libxslt - OpenGL - WebKit - WebKit Canvas Note that only 4th generation models are affected by the vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id91311
    published2016-05-24
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/91311
    titleApple TV < 9.2.1 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(91311);
      script_version("1.9");
      script_cvs_date("Date: 2019/11/14");
    
      script_cve_id(
        "CVE-2016-1801",
        "CVE-2016-1802",
        "CVE-2016-1803",
        "CVE-2016-1807",
        "CVE-2016-1808",
        "CVE-2016-1811",
        "CVE-2016-1813",
        "CVE-2016-1814",
        "CVE-2016-1817",
        "CVE-2016-1818",
        "CVE-2016-1819",
        "CVE-2016-1823",
        "CVE-2016-1824",
        "CVE-2016-1827",
        "CVE-2016-1828",
        "CVE-2016-1829",
        "CVE-2016-1830",
        "CVE-2016-1832",
        "CVE-2016-1833",
        "CVE-2016-1834",
        "CVE-2016-1836",
        "CVE-2016-1837",
        "CVE-2016-1838",
        "CVE-2016-1839",
        "CVE-2016-1840",
        "CVE-2016-1841",
        "CVE-2016-1847",
        "CVE-2016-1854",
        "CVE-2016-1855",
        "CVE-2016-1856",
        "CVE-2016-1857",
        "CVE-2016-1858",
        "CVE-2016-1859",
        "CVE-2016-4650"
      );
      script_xref(name:"APPLE-SA", value:"APPLE-SA-2016-05-16-1");
    
      script_name(english:"Apple TV < 9.2.1 Multiple Vulnerabilities");
      script_summary(english:"Checks the build number.");
    
      script_set_attribute(attribute:"synopsis", value:
    "The remote device is affected by multiple vulnerabilities.");
      script_set_attribute(attribute:"description", value:
    "According to its banner, the version of the remote Apple TV device is
    prior to 9.2.1. It is, therefore, affected by multiple vulnerabilities
    in the following components :
    
      - CFNetwork Proxies
      - CommonCrypto
      - CoreCapture
      - Disk Images
      - ImageIO
      - IOAcceleratorFamily
      - IOHIDFamily
      - Kernel
      - libc
      - libxml2
      - libxslt
      - OpenGL
      - WebKit
      - WebKit Canvas
    
    Note that only 4th generation models are affected by the
    vulnerabilities.");
      script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT206564");
      # https://lists.apple.com/archives/security-announce/2016/May/msg00001.html
      script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?618f77f3");
      script_set_attribute(attribute:"solution", value:
    "Upgrade to Apple TV version 9.2.1 or later. Note that this update is
    only available for 4th generation models.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
      script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-4650");
    
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2016/05/16");
      script_set_attribute(attribute:"patch_publication_date", value:"2016/05/16");
      script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/24");
    
      script_set_attribute(attribute:"plugin_type", value:"remote");
      script_set_attribute(attribute:"cpe", value:"cpe:/a:apple:apple_tv");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_family(english:"Misc.");
    
      script_copyright(english:"This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
    
      script_dependencies("appletv_version.nasl");
      script_require_keys("AppleTV/Version", "AppleTV/Model", "AppleTV/URL", "AppleTV/Port");
      script_require_ports("Services/www", 7000);
    
      exit(0);
    }
    
    include("audit.inc");
    include("appletv_func.inc");
    
    url = get_kb_item('AppleTV/URL');
    if (empty_or_null(url)) exit(0, 'Cannot determine Apple TV URL.');
    port = get_kb_item('AppleTV/Port');
    if (empty_or_null(port)) exit(0, 'Cannot determine Apple TV port.');
    
    build = get_kb_item('AppleTV/Version');
    if (empty_or_null(build)) audit(AUDIT_UNKNOWN_DEVICE_VER, 'Apple TV');
    
    model = get_kb_item('AppleTV/Model');
    if (empty_or_null(model)) exit(0, 'Cannot determine Apple TV model.');
    
    fixed_build = "13Y772";
    tvos_ver = '9.2.1';
    
    # determine gen from the model
    gen = APPLETV_MODEL_GEN[model];
    
    appletv_check_version(
      build          : build,
      fix            : fixed_build,
      affected_gen   : 4,
      fix_tvos_ver   : tvos_ver,
      model          : model,
      gen            : gen,
      port           : port,
      url            : url,
      severity       : SECURITY_HOLE
    );