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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (14.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Linux Kernel
- Debian Linux — versions 10.0
- SUSE Linux Enterprise — versions 12.0, 15.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- syzkaller.appspot.com/bug (Patch, Mailing List)
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Mailing List)
- cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.3 (Patch, Mailing List)
- bugzilla.suse.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- lists.debian.org/debian-lts-announce/2023/07/msg00030.html (mailing-list, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2023/10/msg00027.html (mailing-list, Mailing List, Third Party Advisory)
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.