CVE-2023-34256 — An issue was discovered in the Linux kernel before 6
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 inte
Published
2023-05-31T00:00:00.000Z
Last modified
2025-03-11T15:34:27.715Z
01What is this vulnerability?
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…
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2023-05-31T00:00:00.000Z
- Last modified: 2025-03-11T15:34:27.715Z
09References
- syzkaller.appspot.com — https://syzkaller.appspot.com/bug?extid=8785e41224a3afd04321
- git.kernel.org — https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4f…
- cdn.kernel.org — https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.3
- bugzilla.suse.com — https://bugzilla.suse.com/show_bug.cgi?id=1211895
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2023/07/msg00030.html
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
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