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Fencer Vulns
high 7.8

CVE-2021-39634 json

In fs/eventpoll.c, there is a possible use after free.

published 2022-01-14 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-25991

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

In fs/eventpoll.c, there is a possible use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-204450605References: Upstream kernel

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.8.14-1

debian advisories DEBIAN-CVE-2021-39634

  • linux Ubuntu 16.04 LTS 4.4.0-197.229
  • linux Ubuntu 18.04 LTS 4.15.0-126.129
  • linux Ubuntu 20.04 LTS 5.4.0-56.62
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1118.132
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1088.93
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1030.31
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1088.101~16.04.1
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1030.32

ubuntu advisories UBUNTU-CVE-2021-39634

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

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-24-074-07 updated cvss 7.8

Siemens SIMATIC

  • Siemens SIMATIC RF160B (6GT2003-0FA00) <V2.2
    affected: mitigation “Siemens has released a new version (V2.2) for SIMATIC RF160B and recommends to update to the latest version.” siemens.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • n/a Android

Classification

Weakness

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.