A flaw was found in the grub2-set-bootflag utility of grub2. A local attacker could run this utility under resource pressure (for example by setting RLIMIT), causing grub2 configuration files to be truncated and leaving the system unbootable on subsequent reboots.

The version of grub2 installed on the remote host is prior to 2.06-2. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1684 advisory.

  - A flaw was found in the grub2-set-bootflag utility of grub2. A local attacker could run this utility under     resource pressure (for example by setting RLIMIT), causing grub2 configuration files to be truncated and     leaving the system unbootable on subsequent reboots. (CVE-2019-14865)

  - 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. 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)

  - 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. Variable names present are expanded in the supplied     command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage,     without sufficient bounds checking. If the function is called with a command line that references a     variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack     frame and control execution which could also circumvent Secure Boot protections. The highest threat from     this vulnerability is to data confidentiality and integrity as well as system availability.
    (CVE-2020-27749)

  - 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. 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)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 8 host has packages installed that are affected by a vulnerability as referenced in the CESA-2020:0335 advisory.

  - grub2: grub2-set-bootflag utility causes grubenv corruption rendering the system non-bootable     (CVE-2019-14865)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

From Red Hat Security Advisory 2020:0335 :

An update for grub2 is now available for Red Hat Enterprise Linux 8.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The grub2 packages provide version 2 of the Grand Unified Boot Loader (GRUB), a highly configurable and customizable boot loader with modular architecture. The packages support a variety of kernel formats, file systems, computer architectures, and hardware devices.

Security Fix(es) :

* grub2: grub2-set-bootflag utility causes grubenv corruption rendering the system non-bootable (CVE-2019-14865)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2020:0335 advisory.

  - grub2: grub2-set-bootflag utility causes grubenv corruption rendering the system non-bootable     (CVE-2019-14865)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to the version of the grub2 packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability :

  - A flaw was found in the grub2-set-bootflag utility of     grub2. A local attacker could run this utility under     resource pressure (for example by setting RLIMIT),     causing grub2 configuration files to be truncated and     leaving the system unbootable on subsequent     reboots.(CVE-2019-14865)

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.

According to the version of the grub2 packages installed, the EulerOS installation on the remote host is affected by the following vulnerability :

  - A flaw was found in the grub2-set-bootflag utility of     grub2. A local attacker could run this utility under     resource pressure (for example by setting RLIMIT),     causing grub2 configuration files to be truncated and     leaving the system unbootable on subsequent     reboots.(CVE-2019-14865)

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.

Drop patch fixing a corner case in BLS variable expansion since it may be causing issues

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Fix a grub hidden-menu regression and a bug in blscfg variable expansion

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Security fix for CVE-2019-14865

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Description of changes:

[2.02-78.0.2]
- grub-set-bootflag: fix grubenv update method, fix CVE-2019-14865 [Orabug: 30607067]

Fix a grub hidden-menu regression and a bug in blscfg variable expansion

----

Security fix for CVE-2019-14865

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
151799	Amazon Linux 2 : grub2 (ALAS-2021-1684)	Nessus	Amazon Linux Local Security Checks	high
145972	CentOS 8 : grub2 (CESA-2020:0335)	Nessus	CentOS Local Security Checks	medium
133590	Oracle Linux 8 : grub2 (ELSA-2020-0335)	Nessus	Oracle Linux Local Security Checks	medium
133479	RHEL 8 : grub2 (RHSA-2020:0335)	Nessus	Red Hat Local Security Checks	medium
132799	EulerOS Virtualization for ARM 64 3.0.5.0 : grub2 (EulerOS-SA-2020-1045)	Nessus	Huawei Local Security Checks	medium
132602	EulerOS 2.0 SP8 : grub2 (EulerOS-SA-2020-1009)	Nessus	Huawei Local Security Checks	medium
132408	Fedora 30 : 1:grub2 (2019-69da274284)	Nessus	Fedora Local Security Checks	medium
132305	Oracle Linux 8 : grub2 (ELSA-2019-4869)	Nessus	Oracle Linux Local Security Checks	medium
131465	Fedora 31 : 1:grub2 (2019-e99ebf23c8)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2019-14865

medium

Tenable Plugins

high

medium

medium

medium

medium

medium

medium

medium

medium