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Fencer Vulns
high 7.8

CVE-2021-39698 json

In aio_poll_complete_work of aio.c, there is a possible memory corruption due to a use after free.

published 2022-03-16 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26055

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

In aio_poll_complete_work of aio.c, there is a possible memory corruption due to a 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-185125206References: Upstream kernel

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.15.15-1

debian advisories DEBIAN-CVE-2021-39698

  • linux Ubuntu 20.04 LTS 5.4.0-100.113
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1066.69
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1065.69
  • linux-gke Ubuntu 20.04 LTS 5.4.0-1063.66
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1015.16
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1056.58
  • linux-azure Ubuntu 20.04 LTS 5.4.0-1070.73
  • linux-gkeop Ubuntu 20.04 LTS 5.4.0-1034.35

ubuntu advisories UBUNTU-CVE-2021-39698

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-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.122.2
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.122.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.122.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +9 more 5.14.21-150400.24.122.2
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.122.2
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.122.2
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.122.2.150400.24.58.2
  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, Enterprise Storage 7.1 5.3.18-150300.59.164.1

suse advisories SUSE-SU-2024:2189-1SUSE-SU-2024:2185-1SUSE-SU-2024:2183-1SUSE-SU-2024:2019-1SUSE-SU-2024:2010-1SUSE-SU-2024:2008-1

  • dtb-aarch64 openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-64kb openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-syms openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-source openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-default openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-preempt openSUSE Leap 15.3 5.3.18-150300.59.60.4
  • kernel-kvmsmall openSUSE Leap 15.3 5.3.18-150300.59.60.4

opensuse advisories openSUSE-SU-2022:1039-1

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-2021-39698 updated cvss 7.0

kernel: use-after-free in the file polling implementation

  • Red Hat Virtualization 4 redhat-virtualization-host-image-update
    affected: workaround, no fix available
  • 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 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

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% 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.