CVE-2021-32489: Yubico Yubihsm-Shell

Medium severity, CVSS 4.4. EPSS: 0.9% chance of exploitation in the next 30 days.

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 because response_msg.st.len=8 can be accepted but triggers an integer overflow, which causes CRYPTO_cbc128_decrypt (in OpenSSL) to encounter an undersized buffer and experience a segmentation fault. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

Affected products

• Yubico Yubihsm-Shell: up to and including 2.0.3

Published 2021-05-10. Last modified 2026-06-17.