CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
58.6%
According to the versions of the grub2 packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :
A flaw was found in grub2 in versions prior to 2.06, where it incorrectly enables the usage of the ACPI command when Secure Boot is enabled. This flaw allows an attacker with privileged access to craft a Secondary System Description Table (SSDT) containing code to overwrite the Linux kernel lockdown variable content directly into memory. The table is further loaded and executed by the kernel, defeating its Secure Boot lockdown and allowing the attacker to load unsigned code. The highest threat from this vulnerability is to data confidentiality and integrity, as well as system availability.(CVE-2020-14372)
A flaw was found in grub2 in versions prior to 2.06.
During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2020-25647)
A flaw was found in grub2 in versions prior to 2.06.
Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2021-20233)
A flaw was found in grub2 in versions prior to 2.06.
The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub’s memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2020-27779)
A flaw was found in grub2 in versions prior to 2.06.
The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2021-20225)
A flaw was found in grub2 in versions prior to 2.06.
The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.(CVE-2020-25632)
Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(149104);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/03");
script_cve_id(
"CVE-2020-14372",
"CVE-2020-25632",
"CVE-2020-25647",
"CVE-2020-27779",
"CVE-2021-20225",
"CVE-2021-20233"
);
script_name(english:"EulerOS 2.0 SP3 : grub2 (EulerOS-SA-2021-1794)");
script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
script_set_attribute(attribute:"description", value:
"According to the versions of the grub2 packages installed, the
EulerOS installation on the remote host is affected by the following
vulnerabilities :
- A flaw was found in grub2 in versions prior to 2.06,
where it incorrectly enables the usage of the ACPI
command when Secure Boot is enabled. This flaw allows
an attacker with privileged access to craft a Secondary
System Description Table (SSDT) containing code to
overwrite the Linux kernel lockdown variable content
directly into memory. The table is further loaded and
executed by the kernel, defeating its Secure Boot
lockdown and allowing the attacker to load unsigned
code. The highest threat from this vulnerability is to
data confidentiality and integrity, as well as system
availability.(CVE-2020-14372)
- A flaw was found in grub2 in versions prior to 2.06.
During USB device initialization, descriptors are read
with very little bounds checking and assumes the USB
device is providing sane values. If properly exploited,
an attacker could trigger memory corruption leading to
arbitrary code execution allowing a bypass of the
Secure Boot mechanism. The highest threat from this
vulnerability is to data confidentiality and integrity
as well as system availability.(CVE-2020-25647)
- A flaw was found in grub2 in versions prior to 2.06.
Setparam_prefix() in the menu rendering code performs a
length calculation on the assumption that expressing a
quoted single quote will require 3 characters, while it
actually requires 4 characters which allows an attacker
to corrupt memory by one byte for each quote in the
input. The highest threat from this vulnerability is to
data confidentiality and integrity as well as system
availability.(CVE-2021-20233)
- A flaw was found in grub2 in versions prior to 2.06.
The cutmem command does not honor secure boot locking
allowing an privileged attacker to remove address
ranges from memory creating an opportunity to
circumvent SecureBoot protections after proper triage
about grub's memory layout. The highest threat from
this vulnerability is to data confidentiality and
integrity as well as system
availability.(CVE-2020-27779)
- A flaw was found in grub2 in versions prior to 2.06.
The option parser allows an attacker to write past the
end of a heap-allocated buffer by calling certain
commands with a large number of specific short forms of
options. The highest threat from this vulnerability is
to data confidentiality and integrity as well as system
availability.(CVE-2021-20225)
- A flaw was found in grub2 in versions prior to 2.06.
The rmmod implementation allows the unloading of a
module used as a dependency without checking if any
other dependent module is still loaded leading to a
use-after-free scenario. This could allow arbitrary
code to be executed or a bypass of Secure Boot
protections. The highest threat from this vulnerability
is to data confidentiality and integrity as well as
system availability.(CVE-2020-25632)
Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
# https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2021-1794
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9073f327");
script_set_attribute(attribute:"solution", value:
"Update the affected grub2 packages.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/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:H/UI:N/S:C/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-2021-20233");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"patch_publication_date", value:"2021/04/30");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/04/30");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-common");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64-cdboot");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64-modules");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-pc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-pc-modules");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools-extra");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools-minimal");
script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Huawei Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
script_exclude_keys("Host/EulerOS/uvp_version");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
if (release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0");
sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(3)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP3");
uvp = get_kb_item("Host/EulerOS/uvp_version");
if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP3", "EulerOS UVP " + uvp);
if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);
flag = 0;
pkgs = ["grub2-2.02-0.64.h13",
"grub2-common-2.02-0.64.h13",
"grub2-efi-x64-2.02-0.64.h13",
"grub2-efi-x64-cdboot-2.02-0.64.h13",
"grub2-efi-x64-modules-2.02-0.64.h13",
"grub2-pc-2.02-0.64.h13",
"grub2-pc-modules-2.02-0.64.h13",
"grub2-tools-2.02-0.64.h13",
"grub2-tools-extra-2.02-0.64.h13",
"grub2-tools-minimal-2.02-0.64.h13"];
foreach (pkg in pkgs)
if (rpm_check(release:"EulerOS-2.0", sp:"3", reference:pkg)) flag++;
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : rpm_report_get()
);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "grub2");
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14372
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25632
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25647
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-27779
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20225
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20233
www.nessus.org/u?9073f327
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
58.6%