dbcve.org
Debian LinuxOperating system · Debian

CVE-2023-34319

HIGH · 7.8 CVSS v3.1 Published 2023-09-22
Fix available
A fix is available. Upgrade to 4.10 / 4.14.321 or later.
See remediation →
80/100
Remediation priority · High
Public exploit 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
The fix for XSA-423 added logic to Linux'es netback driver to deal with a frontend splitting a packet in a way such that not all of the headers would come in one piece. Unfortunately the logic introduced there didn't account for the extreme case of the entire packet being split into as many pieces as permitted by the protocol, yet still being smaller than the area that's specially dealt with to keep all (possible) headers together. Such an unusual packet would therefore trigger a buffer overrun in the driver.

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-787

The program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.

General guidance for the out-of-bounds write 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
Debian LinuxOperating system
Affected:= 10.0
Linux KernelOperating system
Affected:>= 4.9.336, < 4.10>= 4.14.302, < 4.14.321>= 4.19.269, < 4.19.290>= 5.4.227, < 5.4.252>= 5.10.159, < 5.10.189>= 5.15.83, < 5.15.125>= 6.1.13, < 6.1.44>= 6.2, < 6.4.9
XenOperating system
Affected:>= 3.2.0

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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 4.10 / 4.14.321 / 4.19.290 or later
Fixed in 4.104.14.3214.19.290
Vendor patch xenbits.xenproject.org →
Recommended fix Moderate confidence

Linux Kernel: 5.4.252+, 4.19.290+, 4.14.321+, or latest stable 5.x/6.x; Debian: 11 or 12; Xen: 4.14.x+

  1. Identify the currently running Linux kernel version using 'uname -r'
  2. Identify the Xen hypervisor version using 'xl version' or 'xm version'
  3. For Linux Kernel: Upgrade to a version beyond the fixed releases: 4.14.321, 4.19.290, or 5.4.252, or preferably the latest stable kernel (5.x or 6.x)
  4. For Debian 10: Upgrade to Debian 11 (bullseye) or Debian 12 (bookworm) which include newer kernels with the fix
  5. For Xen: Upgrade to Xen version 4.14.x or later following the XSA-432 advisory at xenbits.xenproject.org/xsa/advisory-432.html
  6. Reboot the system to load the new kernel/hypervisor
  7. Verify the fix is applied by checking the kernel version and reviewing changelogs for XSA-432
Caveat Kernel upgrades may require rebuild of out-of-tree modules; ensure driver compatibility before upgrading

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

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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-2023-34319 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
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