Amazon Linux AMI update for grub2



Risk Low
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2023-4692
CVE-2023-4693
CWE-ID CWE-787
CWE-125
Exploitation vector Local
Public exploit N/A
Vulnerable software
 Amazon Linux AMI
Operating systems & Components / Operating system

grub2
Operating systems & Components / Operating system package or component

Vendor Amazon Web Services

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Out-of-bounds write

EUVDB-ID: #VU81627

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-4692

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a local user to bypass secure boot protection.

The vulnerability exists due to a boundary error in NTFS driver implementation in grub-core/fs/ntfs.c when parsing the $ATTRIBUTE_LIST attribute for the $MFT file. A local user can pass a specially crafted image to the application, trigger an out-of-bounds write and bypass secure boot protection.

Mitigation

Update the affected packages:

aarch64:
    grub2-efi-aa64-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-modules-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-extra-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-minimal-2.06-61.amzn2023.0.9.aarch64
    grub2-efi-aa64-cdboot-2.06-61.amzn2023.0.9.aarch64
    grub2-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-minimal-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-efi-aa64-ec2-2.06-61.amzn2023.0.9.aarch64
    grub2-debugsource-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-extra-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-debuginfo-2.06-61.amzn2023.0.9.aarch64

noarch:
    grub2-common-2.06-61.amzn2023.0.9.noarch
    grub2-pc-modules-2.06-61.amzn2023.0.9.noarch
    grub2-efi-x64-modules-2.06-61.amzn2023.0.9.noarch
    grub2-efi-aa64-modules-2.06-61.amzn2023.0.9.noarch

src:
    grub2-2.06-61.amzn2023.0.9.src

x86_64:
    grub2-tools-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-modules-2.06-61.amzn2023.0.9.x86_64
    grub2-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-efi-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-extra-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-efi-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-minimal-2.06-61.amzn2023.0.9.x86_64
    grub2-pc-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-ec2-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-minimal-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-extra-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-cdboot-2.06-61.amzn2023.0.9.x86_64
    grub2-debugsource-2.06-61.amzn2023.0.9.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

grub2: All versions

CPE2.3 External links

https://alas.aws.amazon.com/AL2023/ALAS-2023-408.html


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Out-of-bounds read

EUVDB-ID: #VU81628

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-4693

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows an attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition within the NTFS driver in grub-core/fs/ntfs.c when reading data from the resident $DATA attribute. A attacker with physical access to the system use a specially crafted NTFS file system image to read arbitrary memory locations, such as data cached in memory or EFI variables values.

Mitigation

Update the affected packages:

aarch64:
    grub2-efi-aa64-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-modules-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-extra-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-2.06-61.amzn2023.0.9.aarch64
    grub2-emu-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-minimal-2.06-61.amzn2023.0.9.aarch64
    grub2-efi-aa64-cdboot-2.06-61.amzn2023.0.9.aarch64
    grub2-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-minimal-debuginfo-2.06-61.amzn2023.0.9.aarch64
    grub2-efi-aa64-ec2-2.06-61.amzn2023.0.9.aarch64
    grub2-debugsource-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-extra-2.06-61.amzn2023.0.9.aarch64
    grub2-tools-debuginfo-2.06-61.amzn2023.0.9.aarch64

noarch:
    grub2-common-2.06-61.amzn2023.0.9.noarch
    grub2-pc-modules-2.06-61.amzn2023.0.9.noarch
    grub2-efi-x64-modules-2.06-61.amzn2023.0.9.noarch
    grub2-efi-aa64-modules-2.06-61.amzn2023.0.9.noarch

src:
    grub2-2.06-61.amzn2023.0.9.src

x86_64:
    grub2-tools-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-modules-2.06-61.amzn2023.0.9.x86_64
    grub2-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-efi-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-extra-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-efi-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-minimal-2.06-61.amzn2023.0.9.x86_64
    grub2-pc-2.06-61.amzn2023.0.9.x86_64
    grub2-emu-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-ec2-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-minimal-debuginfo-2.06-61.amzn2023.0.9.x86_64
    grub2-tools-extra-2.06-61.amzn2023.0.9.x86_64
    grub2-efi-x64-cdboot-2.06-61.amzn2023.0.9.x86_64
    grub2-debugsource-2.06-61.amzn2023.0.9.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

grub2: All versions

CPE2.3 External links

https://alas.aws.amazon.com/AL2023/ALAS-2023-408.html


Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



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