This is valid for the htpasswd utility of at least apache 1.3.27 and 1.3.28:

The salt used for password generation solely depends on the current 
system time:

(void) srand((int) time((time_t *) NULL));
ap_to64(&salt[0], rand(), 8);

This causes all passwords generated within the same second to have the 
same salt value. This in turn may cause auto-generated default passwords 
to have the same value which could be a point of attack if the password 
file is not properly protected.

The apache team was notified on 23.08.2003 but didn't respond.

Though it would need quite some administrative errors before the above 
could be used it should still be corrected.
-- 
Andreas Steinmetz