Skip to content
Fencer Vulns
medium 5.3

CVE-2021-47477 json

comedi: dt9812: fix DMA buffers on stack

published 2024-05-22 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34482

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

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

comedi: dt9812: fix DMA buffers on stack

USB transfer buffers are typically mapped for DMA and must not be allocated on the stack or transfers will fail.

Allocate proper transfer buffers in the various command helpers and return an error on short transfers instead of acting on random stack data.

Note that this also fixes a stack info leak on systems where DMA is not used as 32 bytes are always sent to the device regardless of how short the command is.

Patch / fix

  • Linux Linux 4.4.292, 4.9.290, 4.14.255, 4.19.217, 5.4.159, 5.10.79, 5.14.18, 5.15.2, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.3-1

debian advisories DEBIAN-CVE-2021-47477

  • 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-2021-47477

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

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +4 more 5.14.21-150500.55.68.1
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1

suse advisories SUSE-SU-2024:2190-1SUSE-SU-2024:2189-1SUSE-SU-2024:2019-1SUSE-SU-2024:2011-1SUSE-SU-2024:2008-1

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-2021-47477 updated cvss 5.1

kernel: comedi: dt9812: fix DMA buffers on stack

  • 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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.72% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.