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Fencer Vulns
medium 6.7

CVE-2021-42739 json

The firewire subsystem in the Linux kernel through 5.14.13 has a buffer overflow related to drivers/media/firewire/firedtv-avc.c and driver…

published 2021-10-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-29699

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

The firewire subsystem in the Linux kernel through 5.14.13 has a buffer overflow related to drivers/media/firewire/firedtv-avc.c and drivers/media/firewire/firedtv-ci.c, because avc_ca_pmt mishandles bounds checking.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.14.16-1

debian advisories DEBIAN-CVE-2021-42739

  • 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-gke Ubuntu 20.04 LTS 5.4.0-1061.64
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1013.14
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1106.108

ubuntu advisories UBUNTU-CVE-2021-42739

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 8 4.18.0-372.9.1.el8
  • perf RHEL 8 4.18.0-372.9.1.el8
  • bpftool RHEL 8 4.18.0-372.9.1.el8
  • kernel-core RHEL 8 4.18.0-372.9.1.el8
  • kernel-tools RHEL 8 4.18.0-372.9.1.el8
  • python3-perf RHEL 8 4.18.0-372.9.1.el8
  • kernel-modules RHEL 8 4.18.0-372.9.1.el8
  • kernel-zfcpdump RHEL 8 4.18.0-372.9.1.el8

red hat advisories RHSA-2022:1988RHSA-2022:1975RHSA-2022:0063RHSA-2022:0065

  • kernel-syms SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.12.14-95.83.2
  • kernel-source SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.12.14-95.83.2
  • kernel-default SLES for SAP 12 SP4, SLES 12 SP4-LTSS, SLE Live Patching 12 SP4 +3 more 4.12.14-95.83.2
  • kernel-syms SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +3 more 4.4.180-94.150.1
  • kernel-source SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +3 more 4.4.180-94.150.1
  • kernel-default SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.150.1
  • kgraft-patch-SLE12-SP3_Update_41 SLES for SAP 12 SP3, SLES 12 SP3-LTSS, OpenStack Cloud Crowbar 8 +2 more 1-4.3.1
  • kernel-syms SLES 12 SP2-BCL 4.4.121-92.161.1

suse advisories SUSE-SU-2022:0328-1SUSE-SU-2022:0327-1SUSE-SU-2022:0325-1SUSE-SU-2022:0298-1SUSE-SU-2022:0296-1SUSE-SU-2022:0295-1

  • kernel-default openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-vanilla openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-kvmsmall openSUSE Leap 15.3 4.12.14-197.102.2
  • kernel-zfcpdump openSUSE Leap 15.3 4.12.14-197.102.2
  • dtb-aarch64 openSUSE Leap 15.3 5.3.18-59.34.1
  • kernel-64kb openSUSE Leap 15.3 5.3.18-59.34.1
  • kernel-syms openSUSE Leap 15.3 5.3.18-59.34.1
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-59.34.1

opensuse advisories openSUSE-SU-2021:3876-1openSUSE-SU-2021:3675-1openSUSE-SU-2021:1477-1openSUSE-SU-2021:3641-1

  • kernel AlmaLinux 8 4.18.0-372.9.1.el8
  • perf AlmaLinux 8 4.18.0-372.9.1.el8
  • bpftool AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-core AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-tools AlmaLinux 8 4.18.0-372.9.1.el8
  • python3-perf AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-modules AlmaLinux 8 4.18.0-372.9.1.el8
  • kernel-debug-core AlmaLinux 8 4.18.0-372.9.1.el8

almalinux advisories ALSA-2022:1988

  • kernel Rocky Linux 8 4.18.0-372.9.1.el8
  • kernel-rt Rocky Linux 8 4.18.0-372.9.1.rt7.166.el8

rocky linux advisories RLSA-2022:1988RLSA-2022:1975

  • kernel CBL-Mariner 2.0 5.10.78.1-1

azure linux advisories AZL-6601

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

  • linux Arch Linux 5.15.1.arch1-1
  • linux-zen Arch Linux 5.15.1.zen1-1
  • linux-lts Arch Linux 5.10.78-1
  • linux-hardened Arch Linux 5.14.17.hardened1-1

arch linux advisories AVG-2530AVG-2531AVG-2532AVG-2540

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-2021-42739 updated cvss 6.7

kernel: Heap buffer overflow in firedtv driver

  • Red Hat Enterprise Linux 7 perf, kernel, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-372.9.1.el8, kernel 4.18.0-372.9.1.el8, bpftool 4.18.0-372.9.1.el8, kernel-core 4.18.0-372.9.1.el8, kernel-tools 4.18.0-372.9.1.el8, python3-perf 4.18.0-372.9.1.el8, +15 more
    fixed: vendor fix RHSA-2022:1988
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.53.1.el7, kernel 3.10.0-1160.53.1.el7, bpftool 3.10.0-1160.53.1.el7, python-perf 3.10.0-1160.53.1.el7, kernel-tools 3.10.0-1160.53.1.el7, kernel-tools-libs 3.10.0-1160.53.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.53.1.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.53.1.el7
    fixed: vendor fix RHSA-2022:0063
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-372.9.1.el8, kernel-debuginfo-common-aarch64 4.18.0-372.9.1.el8, kernel-debuginfo-common-ppc64le 4.18.0-372.9.1.el8
    fixed: vendor fix RHSA-2022:1988
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-trace 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.53.1.rt56.1193.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-kvm 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-trace 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-debug-kvm 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-trace-kvm 3.10.0-1160.53.1.rt56.1193.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.53.1.rt56.1193.el7
    fixed: vendor fix RHSA-2022:0065
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-372.9.1.rt7.166.el8, kernel-rt-kvm 4.18.0-372.9.1.rt7.166.el8, kernel-rt-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-kvm 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-core 4.18.0-372.9.1.rt7.166.el8, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-372.9.1.rt7.166.el8, kernel-rt-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules-extra 4.18.0-372.9.1.rt7.166.el8, +2 more
    fixed: vendor fix RHSA-2022:1975
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.53.1.el7, kernel 3.10.0-1160.53.1.el7, bpftool 3.10.0-1160.53.1.el7, python-perf 3.10.0-1160.53.1.el7, kernel-kdump 3.10.0-1160.53.1.el7, kernel-tools 3.10.0-1160.53.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.53.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.53.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.53.1.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.53.1.el7, kernel 3.10.0-1160.53.1.el7, bpftool 3.10.0-1160.53.1.el7, python-perf 3.10.0-1160.53.1.el7, kernel-tools 3.10.0-1160.53.1.el7, kernel-tools-libs 3.10.0-1160.53.1.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.53.1.el7
    fixed: vendor fix RHSA-2022:0063
show 1 more
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux Client (v. 7) kernel-headers 3.10.0-1160.53.1.el7 Red Hat Enterprise Linux Server (v. 7) kernel-headers 3.10.0-1160.53.1.el7 Red Hat Enterprise Linux Workstation (v. 7) kernel-headers 3.10.0-1160.53.1.el7
    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

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

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.