Vulnerabilities > CVE-2020-9833 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Apple mac OS X

047910
CVSS 4.9 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
NONE
Availability impact
NONE
local
low complexity
apple
CWE-119
nessus

Summary

A memory initialization issue was addressed with improved memory handling. This issue is fixed in macOS Catalina 10.15.5. A local user may be able to read kernel memory.

Vulnerable Configurations

Part Description Count
OS
Apple
163

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.

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);