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 remote NewStart CGSL host, running version MAIN 6.06, has grub2 packages installed that are affected by multiple vulnerabilities:

  - Multiple integer underflows in Grub2 1.98 through 2.02 allow physically proximate attackers to bypass     authentication, obtain sensitive information, or cause a denial of service (disk corruption) via backspace     characters in the (1) grub_username_get function in grub-core/normal/auth.c or the (2) grub_password_get     function in lib/crypto.c, which trigger an Off-by-two or Out of bounds overwrite memory error.
    (CVE-2015-8370)

  - Integer overflow in the LZO algorithm variant in Oberhumer liblzo2 and lzo-2 before 2.07 on 32-bit     platforms might allow remote attackers to execute arbitrary code via a crafted Literal Run.
    (CVE-2014-4607)

  - 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, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper     the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to     load an untrusted or modified kernel, an attacker would first need to establish access to the system such     as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a     networked system with root access. With this access, an attacker could then craft a string to cause a     buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The     highest threat from this vulnerability is to data confidentiality and integrity as well as system     availability. (CVE-2020-10713)

  - In grub2 versions before 2.06 the grub memory allocator doesn't check for possible arithmetic overflows on     the requested allocation size. This leads the function to return invalid memory allocations which can be     further used to cause possible integrity, confidentiality and availability impacts during the boot     process. (CVE-2020-14308)

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

The remote Alibaba Cloud Linux 3 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALINUX3-SA-2021:0026 advisory.

    Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:

    CVE-2019-14865:
    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-2020-10713:
    A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper     the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to     load an untrusted or modified kernel, an attacker would first need to establish access to the system such     as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a     networked system with root access. With this access, an attacker could then craft a string to cause a     buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The     highest threat from this vulnerability is to data confidentiality and integrity as well as system     availability.

    CVE-2020-14308:
    In grub2 versions before 2.06 the grub memory allocator doesn't check for possible arithmetic overflows on     the requested allocation size. This leads the function to return invalid memory allocations which can be     further used to cause possible integrity, confidentiality and availability impacts during the boot     process.

    CVE-2020-14309:
    There's an issue with grub2 in all versions before 2.06 when handling squashfs filesystems containing a     symbolic link with name length of UINT32 bytes in size. The name size leads to an arithmetic overflow     leading to a zero-size allocation further causing a heap-based buffer overflow with attacker controlled     data.

    CVE-2020-14310:
    There is an issue on grub2 before version 2.06 at function read_section_as_string(). It expects a font     name to be at max UINT32_MAX - 1 length in bytes but it doesn't verify it before proceed with buffer     allocation to read the value from the font value. An attacker may leverage that by crafting a malicious     font file which has a name with UINT32_MAX, leading to read_section_as_string() to an arithmetic overflow,     zero-sized allocation and further heap-based buffer overflow.

    CVE-2020-14311:
    There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem     containing a symbolic link with an inode size of UINT32_MAX causes an arithmetic overflow leading to a     zero-sized memory allocation with subsequent heap-based buffer overflow.

    CVE-2020-14372:
    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-2020-15705:
    GRUB2 fails to validate kernel signature when booted directly without shim, allowing secure boot to be     bypassed. This only affects systems where the kernel signing certificate has been imported directly into     the secure boot database and the GRUB image is booted directly without the use of shim. This issue affects     GRUB2 version 2.04 and prior versions.

    CVE-2020-25632:
    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-2020-25647:
    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-2020-27749:
    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-2020-27779:
    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-2021-20225:
    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-2021-20233:
    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.

Tenable has extracted the preceding description block directly from the Alibaba Cloud Linux security advisory.

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

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.

    2024-02-29: CVE-2019-14865 was added to this 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 GRUB 2, 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. 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. 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. 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. 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. 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. 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)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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.

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

    [2.02-78.0.3.el8_1.1]
    - honor /etc/sysconfig/kernel DEFAULTKERNEL setting for BLS [Orabug: 30643497]
    - set EFIDIR as redhat for additional grub2 tools [Orabug: 29875597]
    - Update upstream references [Orabug: 26388226]
    - Copy symvers.gz to /boot during kernel install [Orabug: 29773086]
    - Insert Unbreakable Enterprise Kernel text into BLS config file [Orabug: 29417955]
    - fix symlink removal scriptlet, to be executed only on removal [Orabug: 19231481]
    - Fix comparison in patch for 18504756
    - Remove symlink to grub environment file during uninstall on EFI platforms [Orabug: 19231481]
    - update Oracle Linux certificates (Alexey Petrenko)
    - Put 'with' in menuentry instead of 'using' [Orabug: 18504756]
    - Use different titles for UEK and RHCK kernels [Orabug: 18504756]

    [2.02-78.el8_1.1]
    - grub-set-bootflag: Write new env to tmpfile and then rename (hdegoede)       Resolves: CVE-2019-14865

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

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

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

    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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

----

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.

The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2019-4869 advisory.

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

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

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

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
266249	NewStart CGSL MAIN 6.06 : grub2 Multiple Vulnerabilities (NS-SA-2025-0221)	Nessus	NewStart CGSL Local Security Checks	high
236631	Alibaba Cloud Linux 3 : 0026: grub2 (ALINUX3-SA-2021:0026)	Nessus	Alibaba Cloud Linux Local Security Checks	high
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

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CVE-2019-14865

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Tenable Plugins

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