CVE-2021-43399

HIGH
Published Dec 8, 20214y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Dec 8, 2021 4y ago
Last Modified Jun 17, 2026 2w ago

Description

The Yubico YubiHSM YubiHSM2 library 2021.08, included in the yubihsm-shell project, does not properly validate the length of some operations including SSH signing requests, and some data operations received from a YubiHSM 2 device.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

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

Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-787 Out-of-bounds Write Memory Safety

Affected Products 1

VendorProductVersionRange
yubicoyubihsm_2_software_development_kit* ≤2021.08

References 2

  • blog.inhq.net https://blog.inhq.net/posts/yubico-yubihsm-shell-vuln3/
    ExploitThird Party Advisory
  • yubico.com https://www.yubico.com/support/security-advisories/ysa-2021-04/
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.