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.
{
    "nvd_published_at": "2021-04-14T18:15:00Z",
    "severity": "HIGH",
    "github_reviewed_at": "2021-05-07T16:04:45Z",
    "github_reviewed": true,
    "cwe_ids": [
        "CWE-835"
    ]
}