Fox F120 RL fork mystery fluid - with pics
Sounds like the internal air seals are leaking. This pushes the fluid up and out the upper seals.  

The F120's Air forks should be serviced every 50 hours (similar to all quality forks) , with a full service every hundred hours of riding. Its entirelyt possible its never been serviced. If the fork has not been used in a while, again, possible with a used fork, when you start to use it the seals and go suddenly. 

Check the stanchions - those Fox were prone to wearing the inside of the right stanchion, just above the seal. If the stanchions are worn a repair is uneconomic, otherwise its a run of the mill fork service (Typically $US100-$US150, but pricing depends very much where in the world you live.  If you want to save money and do it yourself there is plenty of detailed information on the net.