Vulnerability in Yubico Yubihsm Connector

CVE-2021-28484

An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.

EPSS: 0.015 (72.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-28484?
CVE-2021-28484 is a high-severity vulnerability in Yubico Yubihsm Connector, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-04-14.
How severe is CVE-2021-28484?
High severity. CVSS v3 base score is 7.5 out of 10.