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Fencer Vulns
high 7.8

CVE-2021-47194 json

cfg80211: call cfg80211_stop_ap when switch from P2P_GO type

published 2024-04-10 2 y ago modified 2026-08-05 3 mo ago also EUVD-2021-33842

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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

cfg80211: call cfg80211_stop_ap when switch from P2P_GO type

If the userspace tools switch from NL80211_IFTYPE_P2P_GO to NL80211_IFTYPE_ADHOC via send_msg(NL80211_CMD_SET_INTERFACE), it does not call the cleanup cfg80211_stop_ap(), this leads to the initialization of in-use data. For example, this path re-init the sdata->assigned_chanctx_list while it is still an element of assigned_vifs list, and makes that linked list corrupt.

Patch / fix

  • Linux Linux 4.4.293, 4.9.291, 4.14.256, 4.19.218, 5.4.162, 5.10.82, 5.15.5, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.5-1

debian advisories DEBIAN-CVE-2021-47194

  • linux Ubuntu 18.04 LTS 4.15.0-167.175
  • linux Ubuntu 20.04 LTS 5.4.0-97.110
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1119.127
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1064.67
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1063.67
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1013.14
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1106.108
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1054.56

ubuntu advisories UBUNTU-CVE-2021-47194

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-syms SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.225.1
  • kernel-source SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.225.1
  • kernel-default SLES for SAP 12 SP5, SLES 12 SP5, SLE Workstation Extension 12 SP5 +2 more 4.12.14-122.225.1
  • kernel-obs-build SLE Software Development Kit 12 SP5 4.12.14-122.225.1
  • kernel-azure SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-16.194.1
  • kernel-syms-azure SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-16.194.1
  • kernel-source-azure SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-16.194.1
  • kernel-rt SLE Real Time 12 SP5 4.12.14-10.197.1

suse advisories SUSE-SU-2024:2940-1SUSE-SU-2024:2901-1SUSE-SU-2024:2892-1SUSE-SU-2024:1663-1SUSE-SU-2024:1659-1SUSE-SU-2024:1650-1

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-2021-47194 updated cvss 5.5

kernel: cfg80211: call cfg80211_stop_ap when switch from P2P_GO type

  • 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: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more
    affected: no fix available
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-core, kernel-tools, python3-perf, +17 more 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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% 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
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

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.