Hello,

how secure or trustable is the mikrotik firmware?
Because we can't look into the source code I have sometimes small concerns that it could be that there are hidden firewall rules implemented.

Are there some evidences available which shows that there are no backdoors in it (after all for example the NASA, US government and NSA are customers of mikrotik products - http://www.mikrotik.com/ourcustomers.php).

Did anyone independent test the mikrotik firmware for backdoors and security bugs like it was made with truecrypt?

Do you meen that NSA and NASA will bought product that is backdoored and expose world secrets to someone who will breach into their network ?? I suppose no.

I think the same concerns should apply to every other major router (e.g. Cisco, HP, Juniper, Brocade) and OS (Microsoft, Apple) vendor on the market, which do not allow you to look into their source code, especially the other ones being American companies, right?

Yes, no device is 100 percent secure but an independent security-test on routerOS would be nice.