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Fencer Vulns
high 7.5

CVE-2025-21844 json

smb: client: Add check for next_buffer in receive_encrypted_standard()

published 2025-03-12 19 mo ago modified 2026-10-15 25 d ago also EUVD-2025-6293

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

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

smb: client: Add check for next_buffer in receive_encrypted_standard()

Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference.

Patch / fix

  • Linux Linux 5.10.235, 5.15.179, 6.1.130, 6.6.80, 6.12.17, 6.13.5, 6.14
  • linux Debian 12 6.1.133-1
  • linux Debian 14, Debian 13 6.12.17-1

debian advisories DEBIAN-CVE-2025-21844

  • linux Ubuntu 22.04 LTS 5.15.0-140.150
  • linux Ubuntu 24.04 LTS 6.8.0-78.78
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1084.91
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1035.37
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1083.92
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1036.38
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1081.87
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1032.36

ubuntu advisories UBUNTU-CVE-2025-21844

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 9 5.14.0-611.5.1.el9_7
  • rv RHEL 9 5.14.0-611.5.1.el9_7
  • perf RHEL 9 5.14.0-611.5.1.el9_7
  • rtla RHEL 9 5.14.0-611.5.1.el9_7
  • libperf RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-rt RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-64k RHEL 9 5.14.0-611.5.1.el9_7
  • kernel-core RHEL 9 5.14.0-611.5.1.el9_7

red hat advisories RHSA-2025:20518RHSA-2025:20095

  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.3.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.3.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1

suse advisories SUSE-SU-2025:01967-1SUSE-SU-2025:01951-1SUSE-SU-2025:01919-1SUSE-SU-2025:20192-1SUSE-SU-2025:20270-1SUSE-SU-2025:20190-1

  • kernel AlmaLinux 10 6.12.0-124.8.1.el10_1
  • rv AlmaLinux 10 6.12.0-124.8.1.el10_1
  • perf AlmaLinux 10 6.12.0-124.8.1.el10_1
  • rtla AlmaLinux 10 6.12.0-124.8.1.el10_1
  • libperf AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-rt AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-64k AlmaLinux 10 6.12.0-124.8.1.el10_1
  • kernel-core AlmaLinux 10 6.12.0-124.8.1.el10_1

almalinux advisories ALSA-2025:20095ALSA-2025:20518

  • kernel Rocky Linux 10 6.12.0-124.8.1.el10_1
  • kernel Rocky Linux 9 5.14.0-611.5.1.el9_7

rocky linux advisories RLSA-2025:20095RLSA-2025:20518

  • kernel Azure Linux 3.0 6.6.82.1-1

azure linux advisories AZL-58518

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-2025-21844 updated cvss 5.5

kernel: smb: client: Add check for next_buffer in receive_encrypted_standard()

  • 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 5.14.0-611.5.1.el9_7, perf 5.14.0-611.5.1.el9_7, rtla 5.14.0-611.5.1.el9_7, python3-perf 5.14.0-611.5.1.el9_7, kernel-devel-matched 5.14.0-611.5.1.el9_7, kernel-64k-devel-matched 5.14.0-611.5.1.el9_7, +7 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.8.1.el10_1, perf 6.12.0-124.8.1.el10_1, rtla 6.12.0-124.8.1.el10_1, python3-perf 6.12.0-124.8.1.el10_1, kernel-devel-matched 6.12.0-124.8.1.el10_1, kernel-64k-devel-matched 6.12.0-124.8.1.el10_1, +7 more
    fixed: vendor fix RHSA-2025:20095
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-611.5.1.el9_7, kernel-64k 5.14.0-611.5.1.el9_7, kernel-core 5.14.0-611.5.1.el9_7, kernel-tools 5.14.0-611.5.1.el9_7, kernel-modules 5.14.0-611.5.1.el9_7, kernel-64k-core 5.14.0-611.5.1.el9_7, +27 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.8.1.el10_1, kernel-64k 6.12.0-124.8.1.el10_1, kernel-core 6.12.0-124.8.1.el10_1, kernel-tools 6.12.0-124.8.1.el10_1, kernel-modules 6.12.0-124.8.1.el10_1, kernel-64k-core 6.12.0-124.8.1.el10_1, +28 more
    fixed: vendor fix RHSA-2025:20095
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-s390x 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-x86_64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-aarch64 5.14.0-611.5.1.el9_7, kernel-debuginfo-common-ppc64le 5.14.0-611.5.1.el9_7
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-aarch64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-ppc64le 6.12.0-124.8.1.el10_1
    fixed: vendor fix RHSA-2025:20095
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-64k 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-64k-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, +14 more
    fixed: vendor fix RHSA-2025:20518
show 4 more
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt-64k 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-modules 6.12.0-124.8.1.el10_1, kernel-rt-64k-core 6.12.0-124.8.1.el10_1, kernel-rt-debug-core 6.12.0-124.8.1.el10_1, +14 more
    fixed: vendor fix RHSA-2025:20095
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-611.5.1.el9_7, kernel-rt-core 5.14.0-611.5.1.el9_7, kernel-rt-modules 5.14.0-611.5.1.el9_7, kernel-rt-debug-core 5.14.0-611.5.1.el9_7, kernel-rt-modules-core 5.14.0-611.5.1.el9_7, kernel-rt-debug-modules 5.14.0-611.5.1.el9_7, +4 more
    fixed: vendor fix RHSA-2025:20518
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-modules 6.12.0-124.8.1.el10_1, kernel-rt-debug-core 6.12.0-124.8.1.el10_1, kernel-rt-modules-core 6.12.0-124.8.1.el10_1, kernel-rt-debug-modules 6.12.0-124.8.1.el10_1, +4 more
    fixed: vendor fix RHSA-2025:20095
  • 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
    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-26-295-16 updated cvss 7.5

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 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

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.