What is CVE-2023-34256?

CVE-2023-34256 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Out-of-bounds Read flaw (CWE-125). CVE-2023-34256 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2023-34256?

CVE-2023-34256 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2023-34256?

No patch is currently available for CVE-2023-34256. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2023-34256 actively exploited?

CVE-2023-34256 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2023-34256

Medium

An issue was discovered in the Linux kernel before 6.3.3. There is an out-of-bounds read in crc16 in lib/crc16.c when called from fs/ext4/super.c because ext4_group_desc_csum does not properly check an offset. NOTE: this is disputed by third parties because the kernel is not intended to defend against attackers with the stated "When modifying the block device while it is mounted by the filesystem" access.

Package Linux Kernel

Published 2023-05-31

Last modified 2025-03-11

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-125

CVE-2023-34256 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2023-34256 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Debian Security
https://lists.debian.org/debian-lts-announce/2023/07/msg00030.html

Mailing List Third Party Advisory
Debian Security
https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html

Mailing List Third Party Advisory
Kernel patch commit
https://bugzilla.suse.com/show_bug.cgi?id=1211895
Patch
Kernel patch commit
https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.3
Patch
Kernel patch commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4f04351888a83e595571de672e0a4a8b74f4fb31
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2023-34256

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2023-05-31

Modified 2025-03-11

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2023-34256?

CVE-2023-34256 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . CVE-2023-34256 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2023-34256?

CVE-2023-34256 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2023-34256?

No patch is currently available for CVE-2023-34256. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2023-34256 actively exploited?

No — CVE-2023-34256 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →