Vulnerabilities > CVE-2018-4243 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Apple products

047910
CVSS 9.3 - CRITICAL
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
apple
CWE-119
critical
nessus
exploit available
NVD
Published: 2018-06-08
Updated: 2018-07-17

Summary

An issue was discovered in certain Apple products. iOS before 11.4 is affected. macOS before 10.13.5 is affected. tvOS before 11.4 is affected. watchOS before 4.3.1 is affected. The issue involves the "Kernel" component. A buffer overflow in getvolattrlist allows attackers to execute arbitrary code in a privileged context via a crafted app.

Vulnerable Configurations

Part Description Count
Application
Apple
57
OS
Apple
306

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.

Exploit-Db

descriptionApple macOS/iOS Kernel - Heap Overflow Due to Lack of Lower Size Check in getvolattrlist. CVE-2018-4243. Dos exploit for Multiple platform. Tags: Heap Overflow
fileexploits/multiple/dos/44848.c
idEDB-ID:44848
last seen2018-06-07
modified2018-06-06
platformmultiple
port
published2018-06-06
reporterExploit-DB
sourcehttps://www.exploit-db.com/download/44848/
titleApple macOS/iOS Kernel - Heap Overflow Due to Lack of Lower Size Check in getvolattrlist
typedos

Nessus

  • NASL familyMisc.
    NASL idAPPLETV_11_4.NASL
    descriptionAccording to its banner, the version of Apple TV on the remote device is prior to 11.4. It is, therefore, affected by multiple vulnerabilities as described in the HT208850 security advisory. Note that only 4th and 5th generation models are affected by these vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id110325
    published2018-06-05
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/110325
    titleApple TV < 11.4 Multiple Vulnerabilities
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(110325);
  script_version("1.6");
  script_cvs_date("Date: 2019/04/05 23:25:06");

  script_cve_id(
    "CVE-2018-4188",
    "CVE-2018-4190",
    "CVE-2018-4192",
    "CVE-2018-4198",
    "CVE-2018-4199",
    "CVE-2018-4200",
    "CVE-2018-4201",
    "CVE-2018-4204",
    "CVE-2018-4206",
    "CVE-2018-4211",
    "CVE-2018-4214",
    "CVE-2018-4218",
    "CVE-2018-4222",
    "CVE-2018-4223",
    "CVE-2018-4224",
    "CVE-2018-4232",
    "CVE-2018-4233",
    "CVE-2018-4235",
    "CVE-2018-4237",
    "CVE-2018-4240",
    "CVE-2018-4241",
    "CVE-2018-4243",
    "CVE-2018-4246",
    "CVE-2018-4249",
    "CVE-2018-5383"
  );
  script_bugtraq_id(
    103957,
    103958,
    103961,
    104378
  );
  script_xref(name:"APPLE-SA", value:"APPLE-SA-2018-6-01-6");

  script_name(english:"Apple TV < 11.4 Multiple Vulnerabilities");
  script_summary(english:"Checks the build number.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Apple TV device is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"According to its banner, the version of Apple TV on the remote device
is prior to 11.4. It is, therefore, affected by multiple
vulnerabilities as described in the HT208850 security advisory.

Note that only 4th and 5th generation models are affected by these
vulnerabilities.");
  script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT208850");
  # https://lists.apple.com/archives/security-announce/2018/Jun/msg00003.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0e8b8fb7");
  # https://lists.apple.com/archives/security-announce/2018/Jul/msg00011.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b0bb7d4f");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Apple TV version 11.4 or later. Note that this update is
only available for 4th and 5th 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: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-2018-4241");
  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:"metasploit_name", value:'Mac OS X libxpc MITM Privilege Escalation');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/06/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/06/05");

  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) 2018-2019 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.');

# https://en.wikipedia.org/wiki/TvOS
# 4th gen model "5,3" and 5th gen model "6,2" share same build
fixed_build = "15L577";
tvos_ver = '11';

# determine gen from the model
gen = APPLETV_MODEL_GEN[model];

appletv_check_version(
  build          : build,
  fix            : fixed_build,
  affected_gen   : make_list(4, 5),
  fix_tvos_ver   : tvos_ver,
  model          : model,
  gen            : gen,
  port           : port,
  url            : url,
  severity       : SECURITY_HOLE
);
  • NASL familyMacOS X Local Security Checks
    NASL idMACOS_10_13_5.NASL
    descriptionThe remote host is running a version of macOS / Mac OS X that is 10.13.x prior to 10.13.5. It is, therefore, affected by multiple vulnerabilities. Note that successful exploitation of the most serious issues can result in arbitrary code execution.
    last seen2020-06-01
    modified2020-06-02
    plugin id110324
    published2018-06-05
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/110324
    titlemacOS 10.13.x < 10.13.5 Multiple Vulnerabilities
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(110324);
  script_version("1.11");
  script_cvs_date("Date: 2019/11/04");

  script_cve_id(
    "CVE-2018-4141",
    "CVE-2018-4159",
    "CVE-2018-4180",
    "CVE-2018-4181",
    "CVE-2018-4182",
    "CVE-2018-4183",
    "CVE-2018-4184",
    "CVE-2018-4193",
    "CVE-2018-4194",
    "CVE-2018-4196",
    "CVE-2018-4198",
    "CVE-2018-4202",
    "CVE-2018-4211",
    "CVE-2018-4217",
    "CVE-2018-4219",
    "CVE-2018-4221",
    "CVE-2018-4223",
    "CVE-2018-4224",
    "CVE-2018-4225",
    "CVE-2018-4226",
    "CVE-2018-4227",
    "CVE-2018-4228",
    "CVE-2018-4229",
    "CVE-2018-4230",
    "CVE-2018-4234",
    "CVE-2018-4235",
    "CVE-2018-4236",
    "CVE-2018-4237",
    "CVE-2018-4240",
    "CVE-2018-4241",
    "CVE-2018-4242",
    "CVE-2018-4243",
    "CVE-2018-4249",
    "CVE-2018-4251",
    "CVE-2018-4253",
    "CVE-2018-4254",
    "CVE-2018-4255",
    "CVE-2018-4256",
    "CVE-2018-4257",
    "CVE-2018-4258",
    "CVE-2018-4404",
    "CVE-2018-4478",
    "CVE-2018-5383",
    "CVE-2018-7584"
  );
  script_bugtraq_id(
    103204,
    104378,
    104879,
    104888,
    104889,
    104897,
    107135
  );
  script_xref(name:"APPLE-SA", value:"APPLE-SA-2018-7-23-2");

  script_name(english:"macOS 10.13.x < 10.13.5 Multiple Vulnerabilities");
  script_summary(english:"Checks the version of Mac OS X / 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 / Mac OS X that is
10.13.x prior to 10.13.5. It is, therefore, affected by multiple
vulnerabilities.

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/HT208849");
  # https://lists.apple.com/archives/security-announce/2018/Jul/msg00009.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?68a789b4");
  script_set_attribute(attribute:"solution", value:
"Upgrade to macOS version 10.13.5 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:N/AC:L/PR:N/UI:N/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-2018-4258");

  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:"metasploit_name", value:'Safari Proxy Object Type Confusion');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/06/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/06/05");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:apple:mac_os_x");
  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) 2018-2019 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, "macOS / Mac OS X");

  c = get_kb_item("Host/OS/Confidence");
  if (c <= 70) exit(1, "Can't determine the host's OS with sufficient confidence.");
}
if (!os) audit(AUDIT_OS_NOT, "macOS / Mac OS X");

matches = pregmatch(pattern:"Mac OS X ([0-9]+(\.[0-9]+)+)", string:os);
if (empty_or_null(matches)) exit(1, "Failed to parse the macOS / Mac OS X version ('" + os + "').");

version = matches[1];
fix = "10.13.5";

if (version !~"^10\.13($|[^0-9])")
  audit(AUDIT_OS_NOT, "macOS 10.13.x");

if (ver_compare(ver:version, fix:fix, strict:FALSE) == -1)
{
  security_report_v4(
    port:0,
    severity:SECURITY_HOLE,
    extra:
      '\n  Installed version : ' + version +
      '\n  Fixed version     : ' + fix +
      '\n'
  );
}
else audit(AUDIT_INST_VER_NOT_VULN, "macOS / Mac OS X", version);

Seebug

bulletinFamilyexploit
descriptiongetvolattrlist takes a user controlled bufferSize argument via the fgetattrlist syscall. When allocating a kernel buffer to serialize the attr list to there's the following comment: ``` /* * Allocate a target buffer for attribute results. * Note that since we won't ever copy out more than the caller requested, * we never need to allocate more than they offer. */ ab.allocated = ulmin(bufferSize, fixedsize + varsize); if (ab.allocated > ATTR_MAX_BUFFER) { error = ENOMEM; VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer size too large (%d limit %d)", ab.allocated, ATTR_MAX_BUFFER); goto out; } MALLOC(ab.base, char *, ab.allocated, M_TEMP, M_ZERO | M_WAITOK); ``` The problem is that the code doesn't then correctly handle the case when the user supplied buffer size is smaller that the requested header size. If we pass ATTR_CMN_RETURNED_ATTRS we'll hit the following code: ``` /* Return attribute set output if requested. */ if (return_valid) { ab.actual.commonattr |= ATTR_CMN_RETURNED_ATTRS; if (pack_invalid) { /* Only report the attributes that are valid */ ab.actual.commonattr &= ab.valid.commonattr; ab.actual.volattr &= ab.valid.volattr; } bcopy(&ab.actual, ab.base + sizeof(uint32_t), sizeof (ab.actual)); } ``` There's no check that the allocated buffer is big enough to hold at least that. Tested on MacOS 10.13.4 (17E199)
idSSV:97333
last seen2018-06-08
modified2018-06-08
published2018-06-08
reporterKnownsec
sourcehttps://www.seebug.org/vuldb/ssvid-97333
titleMacOS/iOS kernel heap overflow due to lack of lower size check in getvolattrlist(CVE-2018-4243)

References