CVE-2025-21640 json
sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
published 2025-01-19 21 mo ago modified 2026-10-15 24 d ago also EUVD-2025-2589
- cvss
- 7.1
- 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:
sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using container_of().
Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is used.
Patch / fix
- Linux Linux 5.4.292, 5.10.234, 5.15.177, 6.1.125, 6.6.72, 6.12.10, 6.13
- linux Debian 12 6.1.128-1
- linux Debian 14, Debian 13 6.12.10-1
debian advisories DEBIAN-CVE-2025-21640
- linux Ubuntu 20.04 LTS 5.4.0-211.231
- linux Ubuntu 22.04 LTS 5.15.0-135.146
- linux Ubuntu 24.04 LTS 6.8.0-60.63
- linux-aws Ubuntu 20.04 LTS 5.4.0-1142.152
- linux-aws Ubuntu 22.04 LTS 5.15.0-1080.87
- linux-aws Ubuntu 24.04 LTS 6.8.0-1029.31
- linux-gcp Ubuntu 20.04 LTS 5.4.0-1145.154
- linux-gcp Ubuntu 22.04 LTS 5.15.0-1079.88
ubuntu advisories UBUNTU-CVE-2025-21640
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-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-2025:0955-1SUSE-SU-2025:0856-1
- git.kernel.org/stable/c/5599b212d2f4466e1832a94e9932684aaa364587 commit
- git.kernel.org/stable/c/03ca51faba2b017bf6c90e139434c4117d0afcdc commit
- git.kernel.org/stable/c/86ddf8118123cb58a0fb8724cad6979c4069065b commit
- git.kernel.org/stable/c/3cd0659deb9c03535fd61839e91d4d4d3e51ac71 commit
- git.kernel.org/stable/c/ad673e514b2793b8d5902f6ba6ab7e890dea23d5 commit
- git.kernel.org/stable/c/f0bb3935470684306e4e04793a20ac4c4b08de0b commit
- git.kernel.org/stable/c/ea62dd1383913b5999f3d16ae99d411f41b528d4 commit
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-2025-21640 updated cvss 5.5
kernel: sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
-
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 moreaffected: no fix planned “Out of support scope”
-
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernelaffected: no fix available “Fix deferred”
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 subsystemaffected: 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
- 24 d ago
Exploit prediction
0.24% 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 | 7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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
- Linux Linux
- Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classification
- Weakness
-
- CWE-476 NULL Pointer Dereference
- Technology feeds
References
- git.kernel.org /stable/c/5599b212d2f4466e1832a94e9932684aaa364587
-
git.kernel.org
/stable/c/03ca51faba2b017bf6c90e139434c4117d0afcdc
patch
-
git.kernel.org
/stable/c/86ddf8118123cb58a0fb8724cad6979c4069065b
patch
-
git.kernel.org
/stable/c/3cd0659deb9c03535fd61839e91d4d4d3e51ac71
patch
-
git.kernel.org
/stable/c/ad673e514b2793b8d5902f6ba6ab7e890dea23d5
patch
-
git.kernel.org
/stable/c/f0bb3935470684306e4e04793a20ac4c4b08de0b
patch
-
git.kernel.org
/stable/c/ea62dd1383913b5999f3d16ae99d411f41b528d4
patch
- lists.debian.org /debian-lts-announce/2025/03/msg00001.html
- lists.debian.org /debian-lts-announce/2025/03/msg00002.html
- cert-portal.siemens.com /productcert/html/ssa-265688.html
Sources
- CVE List CVE-2025-21640
- NVD CVE-2025-21640
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.