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Fencer Vulns
medium 5.7

CVE-2023-1206 json

A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind o…

published 2023-06-30 3 y ago modified 2026-10-14 25 d ago also EUVD-2023-23485

cvss
5.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can increase the CPU usage of the server that accepts IPV6 connections up to 95%.

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 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 6.1.52-1
  • linux Debian 14, Debian 13 6.4.11-1

debian advisories DEBIAN-CVE-2023-1206

  • linux Ubuntu 20.04 LTS 5.4.0-164.181
  • linux Ubuntu 22.04 LTS 5.15.0-86.96
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1111.120
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1047.52
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1115.124
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1044.52
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1044.49
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1058.63

ubuntu advisories UBUNTU-CVE-2023-1206

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

  • perf rhev hypervisor 4.4, RHEL 8.6 EUS 4.18.0-372.75.1.el8_6
  • kernel RHEL 8 4.18.0-513.5.1.el8_9
  • perf RHEL 8 4.18.0-513.5.1.el8_9
  • bpftool RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-core RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-tools RHEL 8 4.18.0-513.5.1.el8_9
  • python3-perf RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-modules RHEL 8 4.18.0-513.5.1.el8_9

red hat advisories RHSA-2023:5627RHSA-2023:5604RHSA-2023:5603RHSA-2023:7077RHSA-2023:6583RHSA-2023:6901

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +4 more 5.14.21-150500.55.31.1
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.31.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.31.1

suse advisories SUSE-SU-2024:0112-1SUSE-SU-2023:4071-1SUSE-SU-2023:4072-2SUSE-SU-2023:4347-1SUSE-SU-2023:4142-1SUSE-SU-2023:4095-1

  • kernel AlmaLinux 8 4.18.0-513.5.1.el8_9
  • perf AlmaLinux 8 4.18.0-513.5.1.el8_9
  • bpftool AlmaLinux 8 4.18.0-513.5.1.el8_9
  • kernel-core AlmaLinux 8 4.18.0-513.5.1.el8_9
  • kernel-tools AlmaLinux 8 4.18.0-513.5.1.el8_9
  • python3-perf AlmaLinux 8 4.18.0-513.5.1.el8_9
  • kernel-modules AlmaLinux 8 4.18.0-513.5.1.el8_9
  • kernel-zfcpdump AlmaLinux 8 4.18.0-513.5.1.el8_9

almalinux advisories ALSA-2023:7077

  • kernel CBL-Mariner 2.0 5.15.126.1-1

azure linux advisories AZL-27382

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-2023-1206 updated cvss 5.7

kernel: hash collisions in the IPv6 connection lookup table

  • 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 “https://access.redhat.com/solutions/30453”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “https://access.redhat.com/solutions/30453”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-aarch64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-ppc64le 4.18.0-513.5.1.el8_9
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:7077
  • Red Hat CodeReady Linux Builder (v. 9) libperf 5.14.0-362.8.1.el9_3, kernel-debuginfo-common-s390x 5.14.0-362.8.1.el9_3, kernel-debuginfo-common-x86_64 5.14.0-362.8.1.el9_3, kernel-debuginfo-common-aarch64 5.14.0-362.8.1.el9_3, kernel-debuginfo-common-ppc64le 5.14.0-362.8.1.el9_3
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6583
  • Red Hat CodeReady Linux Builder EUS (v.8.6) kernel-debuginfo-common-x86_64 4.18.0-372.75.1.el8_6, kernel-debuginfo-common-aarch64 4.18.0-372.75.1.el8_6, kernel-debuginfo-common-ppc64le 4.18.0-372.75.1.el8_6
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5627
  • Red Hat CodeReady Linux Builder EUS (v.9.0) kernel-debuginfo-common-s390x 5.14.0-70.75.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.75.1.el9_0, kernel-debuginfo-common-aarch64 5.14.0-70.75.1.el9_0, kernel-debuginfo-common-ppc64le 5.14.0-70.75.1.el9_0
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5604
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-362.8.1.el9_3, perf 5.14.0-362.8.1.el9_3, rtla 5.14.0-362.8.1.el9_3, kernel-devel-matched 5.14.0-362.8.1.el9_3, kernel-64k-devel-matched 5.14.0-362.8.1.el9_3, kernel-debug-devel-matched 5.14.0-362.8.1.el9_3, +6 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6583
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) perf 5.14.0-70.75.1.el9_0, kernel-devel-matched 5.14.0-70.75.1.el9_0, kernel-debug-devel-matched 5.14.0-70.75.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.75.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.75.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.75.1.el9_0, +2 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5604
show 11 more
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-513.5.1.el8_9, kernel 4.18.0-513.5.1.el8_9, bpftool 4.18.0-513.5.1.el8_9, kernel-core 4.18.0-513.5.1.el8_9, kernel-tools 4.18.0-513.5.1.el8_9, python3-perf 4.18.0-513.5.1.el8_9, +15 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:7077
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.2.0-362.8.1.el9_3, kernel 5.14.0-362.8.1.el9_3, kernel-64k 5.14.0-362.8.1.el9_3, kernel-core 5.14.0-362.8.1.el9_3, kernel-tools 5.14.0-362.8.1.el9_3, python3-perf 5.14.0-362.8.1.el9_3, +28 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6583
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) perf 4.18.0-372.75.1.el8_6, kernel 4.18.0-372.75.1.el8_6, bpftool 4.18.0-372.75.1.el8_6, kernel-core 4.18.0-372.75.1.el8_6, kernel-tools 4.18.0-372.75.1.el8_6, python3-perf 4.18.0-372.75.1.el8_6, +15 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5627
  • Red Hat Enterprise Linux BaseOS EUS (v.9.0) kernel 5.14.0-70.75.1.el9_0, bpftool 5.14.0-70.75.1.el9_0, kernel-core 5.14.0-70.75.1.el9_0, kernel-tools 5.14.0-70.75.1.el9_0, python3-perf 5.14.0-70.75.1.el9_0, kernel-modules 5.14.0-70.75.1.el9_0, +14 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5604
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-core 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-modules 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-core 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-modules 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-modules-extra 4.18.0-513.5.1.rt7.307.el8_9, +2 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6901
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-362.8.1.el9_3, kernel-rt-core 5.14.0-362.8.1.el9_3, kernel-rt-modules 5.14.0-362.8.1.el9_3, kernel-rt-debug-core 5.14.0-362.8.1.el9_3, kernel-rt-modules-core 5.14.0-362.8.1.el9_3, kernel-rt-debug-modules 5.14.0-362.8.1.el9_3, +4 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6583
  • Red Hat Enterprise Linux Real Time EUS (v.9.0) kernel-rt 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-core 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-modules 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-debug-core 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-debug-modules 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-modules-extra 5.14.0-70.75.1.rt21.146.el9_0, +2 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5603
  • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-kvm 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-core 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-modules 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-kvm 4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-core 4.18.0-513.5.1.rt7.307.el8_9, +4 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6901
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-362.8.1.el9_3, kernel-rt-kvm 5.14.0-362.8.1.el9_3, kernel-rt-core 5.14.0-362.8.1.el9_3, kernel-rt-modules 5.14.0-362.8.1.el9_3, kernel-rt-debug-kvm 5.14.0-362.8.1.el9_3, kernel-rt-debug-core 5.14.0-362.8.1.el9_3, +6 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:6583
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.0) kernel-rt 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-kvm 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-core 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-modules 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-debug-kvm 5.14.0-70.75.1.rt21.146.el9_0, kernel-rt-debug-core 5.14.0-70.75.1.rt21.146.el9_0, +4 more
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5603
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 perf 4.18.0-372.75.1.el8_6, kernel-debuginfo-common-x86_64 4.18.0-372.75.1.el8_6
    fixed: vendor fix “https://access.redhat.com/solutions/30453” RHSA-2023:5627

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 5.7

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-25-044-09 updated cvss 5.7

Siemens SCALANCE W700 IEEE 802.11ax

  • Siemens SCALANCE WAB762-1 (6GK5762-1AJ00-6AA0) <V3.0.0 Siemens SCALANCE WAM763-1 (6GK5763-1AL00-7DA0) <V3.0.0 Siemens SCALANCE WAM763-1 (ME) (6GK5763-1AL00-7DC0) <V3.0.0 Siemens SCALANCE WAM763-1 (US) (6GK5763-1AL00-7DB0) <V3.0.0 Siemens SCALANCE WAM766-1 (6GK5766-1GE00-7DA0) <V3.0.0 Siemens SCALANCE WAM766-1 (ME) (6GK5766-1GE00-7DC0) <V3.0.0
    +13 more products
    Siemens SCALANCE WAM766-1 (US) (6GK5766-1GE00-7DB0) <V3.0.0 Siemens SCALANCE WAM766-1 EEC (6GK5766-1GE00-7TA0) <V3.0.0 Siemens SCALANCE WAM766-1 EEC (ME) (6GK5766-1GE00-7TC0) <V3.0.0 Siemens SCALANCE WAM766-1 EEC (US) (6GK5766-1GE00-7TB0) <V3.0.0 Siemens SCALANCE WUB762-1 (6GK5762-1AJ00-1AA0) <V3.0.0 Siemens SCALANCE WUB762-1 iFeatures (6GK5762-1AJ00-2AA0) <V3.0.0 Siemens SCALANCE WUM763-1 (6GK5763-1AL00-3AA0) <V3.0.0 Siemens SCALANCE WUM763-1 (6GK5763-1AL00-3DA0) <V3.0.0 Siemens SCALANCE WUM763-1 (US) (6GK5763-1AL00-3AB0) <V3.0.0 Siemens SCALANCE WUM763-1 (US) (6GK5763-1AL00-3DB0) <V3.0.0 Siemens SCALANCE WUM766-1 (6GK5766-1GE00-3DA0) <V3.0.0 Siemens SCALANCE WUM766-1 (ME) (6GK5766-1GE00-3DC0) <V3.0.0 Siemens SCALANCE WUM766-1 (USA) (6GK5766-1GE00-3DB0) <V3.0.0
    affected: fixed in V3.0.0 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 5.7

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 ICSA-24-046-11 updated cvss 5.7

Siemens SCALANCE XCM-/XRM-300

  • Siemens SCALANCE XCH328 (6GK5328-4TS01-2EC2) <V2.4 Siemens SCALANCE XCM324 (6GK5324-8TS01-2AC2) <V2.4 Siemens SCALANCE XCM328 (6GK5328-4TS01-2AC2) <V2.4 Siemens SCALANCE XCM332 (6GK5332-0GA01-2AC2) <V2.4 Siemens SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3) <V2.4 Siemens SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) <V2.4
    +5 more products
    Siemens SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3) <V2.4
    affected: fixed in V2.4 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
partial
Assessed
2 y ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.7 CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • n/a Kernel
  • 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
  • CWE-400 Uncontrolled Resource Consumption
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.