Denial of service in Yubico yubihsm-shell

Published: 2021-03-05
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2021-27217
Exploitation vector Network
Public exploit N/A
Vulnerable software
Universal components / Libraries / Programming Languages & Components

Vendor Yubico

Security Advisory

This security advisory describes one medium risk vulnerability.

1) Out-of-bounds read

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2021-27217

CWE-ID: CWE-125 - Out-of-bounds Read

Exploit availability: No


The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to a boundary condition when validating the length of authenticated messages during device communication. A remote attacker can send specially crafted data to the system and cause the yubihsm library to fail with a “Not enough space” error.


Install updates from vendor's website.

Vulnerable software versions

yubihsm-shell: 1.0.0, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2019.03, 2019.12, 2020.10, 2021.03

CPE External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.