CVE-2021-3505

MEDIUM
Published Apr 19, 20215y ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Apr 19, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

A flaw was found in libtpms in versions before 0.8.0. The TPM 2 implementation returns 2048 bit keys with ~1984 bit strength due to a bug in the TCG specification. The bug is in the key creation algorithm in RsaAdjustPrimeCandidate(), which is called before the prime number check. The highest threat from this vulnerability is to data confidentiality.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability None

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-331

Affected Products 3

VendorProductVersionRange
libtpms_projectlibtpms* <0.8.0
redhatenterprise_linux8.0any
fedoraprojectfedora33any

References 3

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1950046
    Issue TrackingPatchThird Party Advisory
  • github.com https://github.com/stefanberger/libtpms/issues/183
    ExploitPatchThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NUCZX4S53TUNTSGTCRDNOQZV2V2RI4RJ/

Remediation

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1950046
    Issue TrackingPatchThird Party Advisory
  • github.com https://github.com/stefanberger/libtpms/issues/183
    ExploitPatchThird Party Advisory