MAX2112 is a 7th order low pass filter, so the roll-off is at the rate of 7*20 = 140 dB/decade.
The attenuation at f2 relative to f1 (f2 > f1) in dB will be given by:
A = 140 log10(f2/f1)
So, if the cut off frequency is 4MHz, the attenuation at 24MHz would be 109dB.