Do you consider PWGen safe enough to use? What do you use to make truly random password. PWGen should be using "movement of your mouse" to make it really random, right?
pwgen will seed from
/dev/random if they are available on your system. See randnum.c. I don't have refs, but I am very confident that
/dev/*random has been reviewed for security problems. Since it is critical too, and used by almost every cypto program on a typical linux system.
The source code for pwgen is really pretty small. I am not a security researcher by training, or trade, but I just can't see anywhere that you could hide anything like a backdoor, in a utility that simply returns a string of random random characters or phonemes. There is no network access, there no writing to the filesystem that I see. But feel free to look for yourself source.
I suspect the if an attacker knew you had used pwgen, and knew which options you used, and knew you used one of the options with the phonemes, then they might be able to brute force your password faster than if they attacker assumed your password that was completely random. But that is true for most methods for generating passwords that people can actually remember. Generating longer pwgen passwords should compensate.