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Fencer Intel
medium 5.5

CVE-2021-3446 json

A flaw was found in libtpms in versions before 0.8.2.

published 5y ago modified 4mo ago also EUVD-2021-26772

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

A flaw was found in libtpms in versions before 0.8.2. The commonly used integration of libtpms with OpenSSL contained a vulnerability related to the returned IV (initialization vector) when certain symmetric ciphers were used. Instead of returning the last IV it returned the initial IV to the caller, thus weakening the subsequent encryption and decryption steps. The highest threat from this vulnerability is to data confidentiality.

Patch / fix

  • libtpms_project libtpms 0.8.2
  • libtpms Debian 14, Debian 13, Debian 12 0.8.2-1

debian advisories DEBIAN-CVE-2021-3446

  • libtpms Arch Linux 0.8.2-1

arch linux advisories AVG-1700

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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-2021-3446 updated cvss 5.1

libtpms: return of wrong initialization vector when certain symmetric ciphers are used

  • 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

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a libtpms

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-330 Use of Insufficiently Random Values

References

Sources

Fencer Intel 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.