CVE-2021-3746

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.

Published: 2021-10-19 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3746 is rated Moderate Risk (45.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.90%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3746

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.19% 0.90% +0.71%
2 2025-11-21 0.27% 0.19% -0.08%
3 2025-11-18 — 0.27% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3746

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
7.1 2.0 HIGH
AV:N/AC:M/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 6.9 [email protected]

Weakness enumeration for CVE-2021-3746

OS Trackers for CVE-2021-3746

vendor priority summary link
debian not yet assigned CVE-2021-3746 not yet assigned priority: Debian including 1 source packages (libtpms), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2021-3746
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3746
suse high CVE-2021-3746 severity important: SUSE including 14 source package names (0.45.0.8.14.1:libtpms0-0.8.2-3.3.1, 0.49.0.18.8:libtpms0-0.8.2-3.3.1, …), 24 product×package rows across 18 product lines (Container suse/sles/15.3/virt-launcher, Container suse/sles/15.4/virt-launcher, … (18 product lines)): Fixed 24. https://www.suse.com/security/cve/CVE-2021-3746/
ubuntu medium CVE-2021-3746 medium priority: Ubuntu including 1 source packages (libtpms), 6 status rows across 6 suites (hirsute, impish, jammy, trusty, upstream, xenial): ignored 4, not-affected 1, released 1. https://ubuntu.com/security/CVE-2021-3746

Affected software / configurations for CVE-2021-3746

Vendor Product Version Raw CPE
libtpms_project libtpms >= 0.6.0, < 0.6.6 cpe:2.3:a:libtpms_project:libtpms:*:*:*:*:*:*:*:*
libtpms_project libtpms >= 0.7.0, < 0.7.9 cpe:2.3:a:libtpms_project:libtpms:*:*:*:*:*:*:*:*
libtpms_project libtpms >= 0.8.0, < 0.8.5 cpe:2.3:a:libtpms_project:libtpms:*:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*

References for CVE-2021-3746

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1998588 Issue Tracking Patch Third Party Advisory
cvelogic Threat Intelligence