For an explanation a little more technical, administration is accessible on all ports and all VLANs. No login, just a password of 20 characters. No blocking after x attempts. No attack report. A scriptable version of Linux access exists.
The problem has been valid by the support France & US and they will not do anything yet.
Deconseiller product!
The GS108T seems to have a coherent design after the manual, but having seen the many other firmware problems (outgoing multicast on unauthorized ports regularly sent frames without reason ...), I'll turn to the material in which I have more confidence: CISCO SG200-08, cheaper than the GS108T.