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Fencer Vulns
high 7.8

CVE-2025-21669 json

vsock/virtio: discard packets if the transport changes

published 2025-01-31 21 mo ago modified 2026-10-15 25 d ago also EUVD-2025-2618

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

vsock/virtio: discard packets if the transport changes

If the socket has been de-assigned or assigned to another transport, we must discard any packets received because they are not expected and would cause issues when we access vsk->transport.

A possible scenario is described by Hyunwoo Kim in the attached link, where after a first connect() interrupted by a signal, and a second connect() failed, we can find `vsk->transport` at NULL, leading to a NULL pointer dereference.

Patch / fix

  • Linux Linux 5.10.234, 5.15.177, 6.1.127, 6.6.74, 6.12.11, 6.13
  • linux Debian 12 6.1.128-1
  • linux Debian 14, Debian 13 6.12.11-1

debian advisories DEBIAN-CVE-2025-21669

  • linux Ubuntu 22.04 LTS 5.15.0-135.146
  • linux Ubuntu 24.04 LTS 6.8.0-62.65
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1080.87
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1030.32
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1079.88
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1031.33
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1077.83
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1026.30

ubuntu advisories UBUNTU-CVE-2025-21669

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 RHEL 10.0 6.12.0-55.16.1.el10_0
  • rv RHEL 10.0 6.12.0-55.16.1.el10_0
  • perf RHEL 10.0 6.12.0-55.16.1.el10_0
  • rtla RHEL 10.0 6.12.0-55.16.1.el10_0
  • libperf RHEL 10.0 6.12.0-55.16.1.el10_0
  • kernel-rt RHEL 10.0 6.12.0-55.16.1.el10_0
  • kernel-64k RHEL 10.0 6.12.0-55.16.1.el10_0
  • kernel-core RHEL 10.0 6.12.0-55.16.1.el10_0

red hat advisories RHSA-2025:8669RHSA-2025:6966

  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1.21.6
  • kernel-livepatch-MICRO-6-0_Update_6 Linux Micro 6.1, Linux Micro 6.0 1-3.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
  • kernel-livepatch-MICRO-6-0-RT_Update_6 Linux Micro 6.1, Linux Micro 6.0 1-3.1

suse advisories SUSE-SU-2025:20192-1SUSE-SU-2025:20270-1SUSE-SU-2025:20190-1SUSE-SU-2025:20260-1SUSE-SU-2025:0847-1SUSE-SU-2025:0564-1

  • kernel Rocky Linux 10 6.12.0-55.16.1.el10_0

rocky linux advisories RLSA-2025:8669

  • kernel Azure Linux 3.0 6.6.76.1-1
  • kernel CBL-Mariner 2.0 5.15.180.1-1

azure linux advisories AZL-56393AZL-56411

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-2025-21669 updated cvss 5.5

kernel: vsock/virtio: discard packets if the transport changes

  • 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
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.12.1.el9_6, perf 5.14.0-570.12.1.el9_6, rtla 5.14.0-570.12.1.el9_6, python3-perf 5.14.0-570.12.1.el9_6, kernel-devel-matched 5.14.0-570.12.1.el9_6, kernel-64k-devel-matched 5.14.0-570.12.1.el9_6, +7 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-55.16.1.el10_0, perf 6.12.0-55.16.1.el10_0, rtla 6.12.0-55.16.1.el10_0, python3-perf 6.12.0-55.16.1.el10_0, kernel-devel-matched 6.12.0-55.16.1.el10_0, kernel-64k-devel-matched 6.12.0-55.16.1.el10_0, +7 more
    fixed: vendor fix RHSA-2025:8669
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.12.1.el9_6, kernel-64k 5.14.0-570.12.1.el9_6, kernel-core 5.14.0-570.12.1.el9_6, kernel-tools 5.14.0-570.12.1.el9_6, kernel-modules 5.14.0-570.12.1.el9_6, kernel-64k-core 5.14.0-570.12.1.el9_6, +27 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-55.16.1.el10_0, kernel-64k 6.12.0-55.16.1.el10_0, kernel-core 6.12.0-55.16.1.el10_0, kernel-tools 6.12.0-55.16.1.el10_0, kernel-modules 6.12.0-55.16.1.el10_0, kernel-64k-core 6.12.0-55.16.1.el10_0, +27 more
    fixed: vendor fix RHSA-2025:8669
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.12.1.el9_6
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-55.16.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.16.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.16.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.16.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.16.1.el10_0
    fixed: vendor fix RHSA-2025:8669
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-64k 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-64k-core 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +14 more
    fixed: vendor fix RHSA-2025:6966
show 4 more
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-55.16.1.el10_0, kernel-rt-64k 6.12.0-55.16.1.el10_0, kernel-rt-core 6.12.0-55.16.1.el10_0, kernel-rt-modules 6.12.0-55.16.1.el10_0, kernel-rt-64k-core 6.12.0-55.16.1.el10_0, kernel-rt-debug-core 6.12.0-55.16.1.el10_0, +14 more
    fixed: vendor fix RHSA-2025:8669
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-kvm 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +6 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-55.16.1.el10_0, kernel-rt-kvm 6.12.0-55.16.1.el10_0, kernel-rt-core 6.12.0-55.16.1.el10_0, kernel-rt-modules 6.12.0-55.16.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.16.1.el10_0, kernel-rt-debug-core 6.12.0-55.16.1.el10_0, +6 more
    fixed: vendor fix RHSA-2025:8669
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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-24-102-01 updated cvss 5.5

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

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
13 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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
CNA 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

  • Linux Linux
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

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.