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Fencer Vulns
high 7.8

CVE-2023-34319 json

Linux: buffer overrun in netback due to unusual packet

published 2023-09-22 3 y ago modified 2026-10-15 25 d ago also EUVD-2023-38400

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

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.

Patch / fix

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • linux Debian 12 6.1.52-1
  • linux Debian 14, Debian 13 6.4.11-1

debian advisories DEBIAN-CVE-2023-34319

  • linux Ubuntu 20.04 LTS 5.4.0-165.182
  • linux Ubuntu 22.04 LTS 5.15.0-87.97
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1112.121
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1048.53
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1116.125
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1045.53
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1045.50
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1059.64

ubuntu advisories UBUNTU-CVE-2023-34319

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt SLE Micro 5.5, Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.18.1
  • kernel-syms-rt Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.18.1
  • kernel-rt_debug Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.18.1
  • kernel-source-rt Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.18.1
  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.28.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.28.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.28.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.28.1

suse advisories SUSE-SU-2023:3988-1SUSE-SU-2023:3971-1SUSE-SU-2023:3969-1SUSE-SU-2023:3964-1SUSE-SU-2023:3785-1SUSE-SU-2023:3599-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-34319 updated cvss 5.5

xen: buffer overrun in netback due to unusual packet (XSA-432)

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-23-348-10 updated cvss 7.8

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
16 mo ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.