Out-of-bounds Read in Linux Kernel

CVE-2023-34256

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.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (16.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-34256?
CVE-2023-34256 is a medium-severity vulnerability in Linux Kernel, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2023-05-31.
How severe is CVE-2023-34256?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2023-34256 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.