int qemu_uuid_parse(const char *str, uint8_t *uuid)
{
    int ret;

    if (strlen(str) != 36) {
        return -1;
    }

    ret = sscanf(str, UUID_FMT, &uuid[0], &uuid[1], &uuid[2], &uuid[3],
                 &uuid[4], &uuid[5], &uuid[6], &uuid[7], &uuid[8], &uuid[9],
                 &uuid[10], &uuid[11], &uuid[12], &uuid[13], &uuid[14],
                 &uuid[15]);

    if (ret != 16) {
        return -1;
    }
    return 0;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.