Linux KernelOperating system · Linux

CVE-2023-44466

HIGH · 8.8 CVSS v3.1 Published 2023-09-29
Fix available
A fix is available. Upgrade to 5.15.121 / 6.1.40 or later.
See remediation →
94/100
Remediation priority · Urgent
Public exploit Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in net/ceph/messenger_v2.c in the Linux kernel before 6.4.5. There is an integer signedness error, leading to a buffer overflow and remote code execution via HELLO or one of the AUTH frames. This occurs because of an untrusted length taken from a TCP packet in ceph_decode_32.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-120

A fixed-size buffer is filled without checking the length of the incoming data, so it overflows into neighbouring memory. This is the classic overflow attackers use to overwrite return addresses and hijack execution. The fix is strict length checks and safe, bounded string and memory functions.

General guidance for the classic buffer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.11, < 5.15.121>= 5.16, < 6.1.40>= 6.2, < 6.4.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.15.121 / 6.1.40 / 6.4.5 or later
Fixed in 5.15.1216.1.406.4.5
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.4.5 or later (or 5.15.121+/6.1.40+ for LTS branches)

  1. 1. Identify current kernel version using `uname -r`
  2. 2. Plan for system downtime (kernel upgrade requires reboot)
  3. 3. Upgrade the Linux kernel to version 6.4.5 or later, or alternatively to 5.15.121+ / 6.1.40+ for LTS branches
  4. 4. Verify the fix is included by checking that the kernel version includes commit a282a2f10539dce2aa619e71e1817570d557fc97
  5. 5. Update boot loader configuration if needed
  6. 6. Reboot the system into the new kernel
  7. 7. Verify the system boots successfully and the kernel version is correct using `uname -r`
Caveat Kernel upgrades may require verification of drivers and software compatibility; jumping multiple minor versions should be tested in a staging environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,200. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-44466 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-44466 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data