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.
{
"unresolved_ranges": [
{
"extracted_events": [
{
"introduced": "34"
},
{
"last_affected": "34"
}
],
"vendor_product": "fedoraproject:fedora",
"source": "CPE_STRING",
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
]
}
]
}{
"cpe": "cpe:2.3:a:yubico:yubihsm_connector:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "3.0.1"
}
],
"source": "CPE_RANGE"
}