Vulnerabilities > CVE-2020-9852 - Integer Overflow or Wraparound 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-190
nessus

Summary

An integer overflow was addressed through improved input validation. This issue is fixed in iOS 13.5 and iPadOS 13.5, macOS Catalina 10.15.5, tvOS 13.4.5, watchOS 6.2.5. A malicious application may be able to execute arbitrary code with kernel privileges.

Vulnerable Configurations

Part Description Count
OS
Apple
542

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Forced Integer Overflow
    This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.

Nessus

NASL familyMacOS X Local Security Checks
NASL idMACOS_HT211170.NASL
descriptionThe remote host is running a version of macOS / Mac OS X that is 10.15.x prior to 10.15.5, 10.13.x prior to 10.13.6 Security Update 2020-003, 10.14.x prior to 10.14.6 Security Update 2020-003. It is, therefore, affected by multiple vulnerabilities: - In ksh version 20120801, a flaw was found in the way it evaluates certain environment variables. An attacker could use this flaw to override or bypass environment restrictions to execute shell commands. Services and applications that allow remote unauthenticated attackers to provide one of those environment variables could allow them to exploit this issue remotely. (CVE-2019-14868) - In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zmodload with a module that calls setuid(). (CVE-2019-20044) - An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. Processing a maliciously crafted image may lead to arbitrary code execution. (CVE-2020-3878) Note that Nessus has not tested for this issue but has instead relied only on the operating system
last seen2020-06-12
modified2020-05-28
plugin id136930
published2020-05-28
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/136930
titlemacOS 10.15.x < 10.15.5 / 10.14.x < 10.14.6 Security Update 2020-003 / 10.13.x < 10.13.6 Security Update 2020-003
code
#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(136930);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/07/17");

  script_cve_id(
    "CVE-2019-14868",
    "CVE-2019-20044",
    "CVE-2020-3878",
    "CVE-2020-3882",
    "CVE-2020-9771",
    "CVE-2020-9772",
    "CVE-2020-9788",
    "CVE-2020-9789",
    "CVE-2020-9790",
    "CVE-2020-9791",
    "CVE-2020-9792",
    "CVE-2020-9793",
    "CVE-2020-9794",
    "CVE-2020-9795",
    "CVE-2020-9797",
    "CVE-2020-9804",
    "CVE-2020-9808",
    "CVE-2020-9809",
    "CVE-2020-9811",
    "CVE-2020-9812",
    "CVE-2020-9813",
    "CVE-2020-9814",
    "CVE-2020-9815",
    "CVE-2020-9816",
    "CVE-2020-9817",
    "CVE-2020-9821",
    "CVE-2020-9822",
    "CVE-2020-9824",
    "CVE-2020-9825",
    "CVE-2020-9826",
    "CVE-2020-9827",
    "CVE-2020-9828",
    "CVE-2020-9830",
    "CVE-2020-9831",
    "CVE-2020-9832",
    "CVE-2020-9833",
    "CVE-2020-9834",
    "CVE-2020-9837",
    "CVE-2020-9839",
    "CVE-2020-9841",
    "CVE-2020-9842",
    "CVE-2020-9844",
    "CVE-2020-9847",
    "CVE-2020-9851",
    "CVE-2020-9852",
    "CVE-2020-9855",
    "CVE-2020-9856",
    "CVE-2020-9857"
  );
  script_xref(name:"APPLE-SA", value:"HT211170");
  script_xref(name:"APPLE-SA", value:"APPLE-SA-2020-05-18");
  script_xref(name:"IAVA", value:"2020-A-0227-S");

  script_name(english:"macOS 10.15.x < 10.15.5 / 10.14.x < 10.14.6 Security Update 2020-003 / 10.13.x < 10.13.6 Security Update 2020-003");

  script_set_attribute(attribute:"synopsis", value:
"The remote host is missing a macOS update that fixes multiple vulnerabilities");
  script_set_attribute(attribute:"description", value:
"The remote host is running a version of macOS / Mac OS X that is 10.15.x prior to 10.15.5, 10.13.x prior to 10.13.6
Security Update 2020-003, 10.14.x prior to 10.14.6 Security Update 2020-003. It is, therefore, affected by multiple
vulnerabilities:

  - In ksh version 20120801, a flaw was found in the way it
    evaluates certain environment variables. An attacker
    could use this flaw to override or bypass environment
    restrictions to execute shell commands. Services and
    applications that allow remote unauthenticated attackers
    to provide one of those environment variables could
    allow them to exploit this issue remotely.
    (CVE-2019-14868)

  - In Zsh before 5.8, attackers able to execute commands
    can regain privileges dropped by the --no-PRIVILEGED
    option. Zsh fails to overwrite the saved uid, so the
    original privileges can be restored by executing
    MODULE_PATH=/dir/with/module zmodload with a module that
    calls setuid(). (CVE-2019-20044)

  - An out-of-bounds read was addressed with improved input
    validation. This issue is fixed in iOS 13.3.1 and iPadOS
    13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS
    6.1.2. Processing a maliciously crafted image may lead
    to arbitrary code execution. (CVE-2020-3878)

Note that Nessus has not tested for this issue but has instead relied only on the operating system's self-reported
version number.");
  script_set_attribute(attribute:"see_also", value:"https://support.apple.com/en-us/HT211170");
  script_set_attribute(attribute:"solution", value:
"Upgrade to macOS 10.15.5 / 10.14.x < 10.14.6 Security Update 2020-003 / 10.13.x < 10.13.6 Security Update 2020-003 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:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-9852");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/28");

  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_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"MacOS X Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 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('lists.inc');
include('vcf_extras_apple.inc'); 

app_info = vcf::apple::macos::get_app_info();

constraints = [
  { 'max_version' : '10.15.4', 'min_version' : '10.15', 'fixed_build' : '19F96', 'fixed_display' : 'macOS Catalina 10.15.5' },
  { 'max_version' : '10.13.6', 'min_version' : '10.13', 'fixed_build' : '17G13033', 'fixed_display' : '10.13.6 Security Update 2020-003' },
  { 'max_version' : '10.14.6', 'min_version' : '10.14', 'fixed_build' : '18G5033', 'fixed_display' : '10.14.6 Security Update 2020-003' }
];

vcf::apple::macos::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);