CVE-2021-20233 – grub2: Heap out-of-bounds write due to miscalculation of space required for quoting
https://notcve.org/view.php?id=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. Se encontró un fallo en grub2 en versiones anteriores a 2.06. La función Setparam_prefix() en el código de renderización del menú lleva a cabo un cálculo de longitud asumiendo que expresar una comilla simple entre comillas requerirá 3 caracteres, mientras que actualmente requiere 4 caracteres, lo que permite a un atacante corromper la memoria por un byte para cada comilla en la entrada. • https://bugzilla.redhat.com/show_bug.cgi?id=1926263 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWZ36QK4IKU6MWDWNOOWKPH3WXZBHT2R https://security.gentoo.org/glsa/202104-05 https://security.netapp.com/advisory/ntap-20220325-0001 https://access.redhat.com/security/cve/CVE-2021-20233 • CWE-787: Out-of-bounds Write •
CVE-2020-15705 – GRUB2: avoid loading unsigned kernels when GRUB is booted directly under secureboot without shim
https://notcve.org/view.php?id=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. GRUB2 presenta un fallo al comprobar la firma del kernel cuando se inicia directamente sin cuña, permitiendo que el arranque seguro sea omitido. Esto solo afecta a los sistemas en los que el certificado de firma del kernel ha sido importado directamente a la base de datos de arranque seguro y la imagen de GRUB es iniciada directamente sin el uso de cuña. • http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00067.html http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00069.html http://ubuntu.com/security/notices/USN-4432-1 http://www.openwall.com/lists/oss-security/2020/07/29/3 http://www.openwall.com/lists/oss-security/2021/03/02/3 http://www.openwall.com/lists/oss-security/2021/09/17/2 http://www.openwall.com/lists/oss-security/2021/09/17/4 http://www.openwall.com/lists/oss-security • CWE-347: Improper Verification of Cryptographic Signature CWE-440: Expected Behavior Violation •
CVE-2020-15706 – GRUB2 contains a race condition leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing.
https://notcve.org/view.php?id=CVE-2020-15706
GRUB2 contains a race condition in grub_script_function_create() leading to a use-after-free vulnerability which can be triggered by redefining a function whilst the same function is already executing, leading to arbitrary code execution and secure boot restriction bypass. This issue affects GRUB2 version 2.04 and prior versions. GRUB2 contiene una condición de carrera en la función grub_script_function_create() que conlleva a una vulnerabilidad de uso de la memoria previamente liberada la cual puede ser desencadenada al redefinir una función mientras la misma función ya se está ejecutando, conllevando a una ejecución de código arbitrario y a una omisión de restricción de arranque seguro. Este problema afecta a GRUB2 versiones 2.04 y versiones anteriores • http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html http://ubuntu.com/security/notices/USN-4432-1 http://www.openwall.com/lists/oss-security/2020/07/29/3 https://access.redhat.com/security/vulnerabilities/grub2bootloader https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011 https://security.gentoo.org/ • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') CWE-416: Use After Free •
CVE-2020-10713 – grub2: Crafted grub.cfg file can lead to arbitrary code execution during boot process
https://notcve.org/view.php?id=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. • http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html http://www.openwall.com/lists/oss-security/2020/07/29/3 https://bugzilla.redhat.com/show_bug.cgi?id=1825243 https://cve.openeuler.org/#/CVEInfo/CVE-2020-10713 https://eclypsium.com/2020/07/29/theres-a-hole-in-the-boot https://kb.vmware.com/s/article/80181 https://security.gentoo.org/glsa/202104-05 https://security. • CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') •
CVE-2020-14311 – grub2: Integer overflow in grub_ext2_read_link leads to heap-based buffer overflow
https://notcve.org/view.php?id=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. Se presenta un problema con grub2 versiones anteriores a 2.06, mientras se maneja un symlink en los sistemas de archivos ext. Un sistema de archivos que contiene un enlace simbólico con un tamaño de inode de UINT32_MAX causa un desbordamiento aritmético conllevando a una asignación de memoria de tamaño cero con el posterior desbordamiento del búfer en la región heap de la memoria A flaw was found in grub2 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 a subsequent heap-based buffer overflow. • http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.html http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.html http://www.openwall.com/lists/oss-security/2021/09/17/2 http://www.openwall.com/lists/oss-security/2021/09/17/4 http://www.openwall.com/lists/oss-security/2021/09/21/1 https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14311 https://security.gentoo.org/glsa/202104-05 https://usn.ubuntu.com/4432-1 https://acce • CWE-122: Heap-based Buffer Overflow CWE-190: Integer Overflow or Wraparound •