CVE-2021-27217

medium

Description

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

References

https://www.yubico.com/support/security-advisories/ysa-2021-01/

https://github.com/Yubico/yubihsm-shell/releases

https://blog.inhq.net/posts/yubico-libyubihsm-vuln2

Details

Source: Mitre, NVD

Published: 2021-03-04

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 3.5

Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:N/A:P

Severity: Low

CVSS v3

Base Score: 4.4

Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00615