WebFacing security

It seem's to me that's quite trivial for an end user of wabfaced 
application
to recognize the WFLogon servlet parameter clcmd and I find myself trying
URL like:


http://myserver/myappl/WFLogon?clcmd=CRTPF+FILE(MYLIB/MYFILE)+RCDLEN(120)

or
   http://myserver/myappl/WFLogon?clcmd=DLTF+FILE(MYLIB\MYFILE)

and they, not surprising, WORKS!

Oh yes, I con use invocation files to obfuscate the clcmd mode but it's 
not an answer; 
oh yes, there is the OS security but that wasn't an issue for 
pre-WebFacing
shops and so ....

I'm thinking about a j2ee filter on WFLogon pattern, combined with a proxy
program that work on prefixed command (someting like
CALL+MYPROG+PARM(CMDCODE CMDPARMS ...)... 

but i hope i'm over estimating the "problem".
Had someone already considered this ?  
Am i too scared the this issue ?

thank you