RHEL 8 : grub2, mokutil, shim, and shim-unsigned-x64 (RHSA-2022:5096)

high Nessus Plugin ID 162326

Synopsis

The remote Red Hat host is missing one or more security updates for grub2 / mokutil / shim / shim-unsigned-x64.

Description

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2022:5096 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.

The shim package contains a first-stage UEFI boot loader that handles chaining to a trusted full boot loader under secure boot environments.

Security Fix(es):

* grub2: Integer underflow in grub_net_recv_ip4_packets (CVE-2022-28733)

* grub2: Crafted PNG grayscale images may lead to out-of-bounds write in heap (CVE-2021-3695)

* grub2: Crafted PNG image may lead to out-of-bound write during huffman table handling (CVE-2021-3696)

* grub2: Crafted JPEG image can lead to buffer underflow write in the heap (CVE-2021-3697)

* grub2: Out-of-bound write when handling split HTTP headers (CVE-2022-28734)

* grub2: shim_lock verifier allows non-kernel files to be loaded (CVE-2022-28735)

* grub2: use-after-free in grub_cmd_chainloader() (CVE-2022-28736)

* shim: Buffer overflow when loading crafted EFI images (CVE-2022-28737)

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 these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL grub2 / mokutil / shim / shim-unsigned-x64 packages based on the guidance in RHSA-2022:5096.

See Also

http://www.nessus.org/u?3ec4a68c

https://access.redhat.com/security/updates/classification/#important

https://access.redhat.com/errata/RHSA-2022:5096

https://bugzilla.redhat.com/show_bug.cgi?id=1991685

https://bugzilla.redhat.com/show_bug.cgi?id=1991686

https://bugzilla.redhat.com/show_bug.cgi?id=1991687

https://bugzilla.redhat.com/show_bug.cgi?id=2083339

https://bugzilla.redhat.com/show_bug.cgi?id=2090463

https://bugzilla.redhat.com/show_bug.cgi?id=2090857

https://bugzilla.redhat.com/show_bug.cgi?id=2090899

https://bugzilla.redhat.com/show_bug.cgi?id=2092613

Plugin Details

Severity: High

ID: 162326

File Name: redhat-RHSA-2022-5096.nasl

Version: 1.11

Type: local

Agent: unix

Published: 6/16/2022

Updated: 11/7/2024

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2021-3696

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2022-28733

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:grub2-tools-minimal, p-cpe:/a:redhat:enterprise_linux:grub2-tools, p-cpe:/a:redhat:enterprise_linux:shim-unsigned-x64, p-cpe:/a:redhat:enterprise_linux:grub2-efi-x64-cdboot, p-cpe:/a:redhat:enterprise_linux:grub2-efi-aa64, p-cpe:/a:redhat:enterprise_linux:grub2-efi-ia32-modules, p-cpe:/a:redhat:enterprise_linux:grub2-pc-modules, p-cpe:/a:redhat:enterprise_linux:grub2-tools-extra, p-cpe:/a:redhat:enterprise_linux:grub2-efi-aa64-modules, cpe:/o:redhat:rhel_eus:8.4, p-cpe:/a:redhat:enterprise_linux:shim-ia32, p-cpe:/a:redhat:enterprise_linux:grub2-common, p-cpe:/a:redhat:enterprise_linux:shim-x64, p-cpe:/a:redhat:enterprise_linux:grub2-efi-x64, p-cpe:/a:redhat:enterprise_linux:shim-aa64, p-cpe:/a:redhat:enterprise_linux:grub2, p-cpe:/a:redhat:enterprise_linux:grub2-pc, p-cpe:/a:redhat:enterprise_linux:grub2-efi-ia32-cdboot, p-cpe:/a:redhat:enterprise_linux:grub2-efi-ia32, p-cpe:/a:redhat:enterprise_linux:grub2-efi-x64-modules, p-cpe:/a:redhat:enterprise_linux:grub2-efi-aa64-cdboot, p-cpe:/a:redhat:enterprise_linux:grub2-ppc64le, p-cpe:/a:redhat:enterprise_linux:grub2-tools-efi, p-cpe:/a:redhat:enterprise_linux:shim, p-cpe:/a:redhat:enterprise_linux:grub2-ppc64le-modules

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 6/16/2022

Vulnerability Publication Date: 6/16/2022

Reference Information

CVE: CVE-2021-3695, CVE-2021-3696, CVE-2021-3697, CVE-2022-28733, CVE-2022-28734, CVE-2022-28735, CVE-2022-28736, CVE-2022-28737

CWE: 120, 191, 416, 787, 829

RHSA: 2022:5096