When the NSA leaks happened, investigates this and promoted this as a possible attack vector.
NOTE - You can generate a new set of moduli like so:
# ssh-keygen -G moduli-2048.candidates -b 2048
# ssh-keygen -T moduli-2048 -f moduli-2048.candidates
Put the results in /etc/ssh/moduli
WARNING: This takes forever. Also, according to man ssh-keygen:
It is important that this file contains moduli of a range of bit lengths and that both ends of a connection share common moduli.
It's not possible to regenerate and share many moduli quickly - hence the reuse of moduli. SSH has support for x25519 algorithms - this definitely means I'll be moving away from pre-computed DH moduli also.