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Fencer Vulns
medium 6.5

CVE-2021-3746 json

A flaw was found in the libtpms code that may cause access beyond the boundary of internal buffers.

published 2021-10-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27022

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

A flaw was found in the libtpms code that may cause access beyond the boundary of internal buffers. The vulnerability is triggered by specially-crafted TPM2 command packets that then trigger the issue when the state of the TPM2's volatile state is written. The highest threat from this vulnerability is to system availability. This issue affects libtpms versions before 0.8.5, before 0.7.9 and before 0.6.6.

Patch / fix

  • libtpms_project libtpms 0.6.6, 0.7.9, 0.8.5
  • libtpms Debian 14, Debian 13, Debian 12 0.9.1-1

debian advisories DEBIAN-CVE-2021-3746

  • libtpms SLE Module for Server Applications 15 SP3, SLE Micro 5.1 0.8.2-3.3.1

suse advisories SUSE-SU-2021:3004-2SUSE-SU-2021:3004-1

  • libtpms openSUSE Leap 15.3 0.8.2-3.3.1

opensuse advisories openSUSE-SU-2021:3004-1

  • libtpms Arch Linux 0.8.5-1

arch linux advisories AVG-2327

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-2021-3746 updated cvss 6.5

libtpms: out-of-bounds access via specially crafted TPM 2 command packets

  • Red Hat Enterprise Linux 8 Advanced Virtualization libtpms
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 libtpms
    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

0.97% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 7.1 AV:N/AC:M/Au:N/C:N/I:N/A:C

Affected products

  • n/a libtpms

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.