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Fencer Vulns
medium 6.5

CVE-2023-42755 json

Kernel: rsvp: out-of-bounds read in rsvp_classify()

published 2023-10-05 3 y ago modified 2026-11-07 2 d ago also EUVD-2023-47187

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the `rsvp_classify` function. This issue may allow a local user to crash the system and cause a denial of service.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 8 0:4.18.0-553.el8_10, 0:4.18.0-553.rt7.342.el8_10
  • 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 SIMATIC S7-1500 TM MFP - GNU/Linux subsystem V1.1
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • linux Debian 12 6.1.55-1
  • linux Debian 14, Debian 13 6.3.7-1

debian advisories DEBIAN-CVE-2023-42755

  • 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-2023-42755

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 RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.rt7.342.el8_10

red hat advisories RHSA-2024:2950RHSA-2024:3138

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +4 more 5.14.21-150500.55.68.1
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1

suse advisories SUSE-SU-2024:2190-1SUSE-SU-2024:2184-1SUSE-SU-2024:2019-1SUSE-SU-2024:2008-1SUSE-SU-2024:1983-1SUSE-SU-2024:1979-1

  • kernel-rt AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-kvm AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-kvm AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.rt7.342.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.rt7.342.el8_10

almalinux advisories ALSA-2024:2950ALSA-2024:3138

  • kernel Rocky Linux 8 4.18.0-553.123.1.el8_10.cloud.0.1
  • kernel-rt Rocky Linux 8 4.18.0-553.rt7.342.el8_10
  • kernel Rocky Linux 8 4.18.0-553.el8_10

rocky linux advisories RXSA-2024:3138RLSA-2024:2950RLSA-2024:3138

  • kernel CBL-Mariner 2.0 5.15.135.1-2

azure linux advisories AZL-31269

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2023-42755 updated cvss 6.5

kernel: rsvp: out-of-bounds read in rsvp_classify()

  • 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
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.el8_10, kernel 4.18.0-553.el8_10, bpftool 4.18.0-553.el8_10, kernel-core 4.18.0-553.el8_10, kernel-tools 4.18.0-553.el8_10, python3-perf 4.18.0-553.el8_10, +15 more Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.el8_10
    fixed: vendor fix RHSA-2024:3138
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.rt7.342.el8_10, kernel-rt-kvm 4.18.0-553.rt7.342.el8_10, kernel-rt-core 4.18.0-553.rt7.342.el8_10, kernel-rt-modules 4.18.0-553.rt7.342.el8_10, kernel-rt-debug-kvm 4.18.0-553.rt7.342.el8_10, kernel-rt-debug-core 4.18.0-553.rt7.342.el8_10, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.rt7.342.el8_10, kernel-rt-core 4.18.0-553.rt7.342.el8_10, kernel-rt-modules 4.18.0-553.rt7.342.el8_10, kernel-rt-debug-core 4.18.0-553.rt7.342.el8_10, kernel-rt-debug-modules 4.18.0-553.rt7.342.el8_10, kernel-rt-modules-extra 4.18.0-553.rt7.342.el8_10, +2 more
    fixed: vendor fix RHSA-2024:2950
  • 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 6.5

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 ICSA-23-166-11 updated cvss 6.5

Siemens SIMATIC S7-1500 TM MFP Linux Kernel

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
partial
Assessed
16 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • seclists.org https://seclists.org/oss-sec/2023/q3/229 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 9
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • 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.