My administrator installed the coldfusion-security-hotfix-apsb13-03 and now I am getting 500 server errors when trying to submit forms. Added the var postparametersLimit because we have some large forms but I am still getting the error. Running cf 9.0.1.
Check this link. It should help you resolve our issue. Your webhost will need to make modifications to the CF installation on the web server.
I had the same issue and adding the postParametersLimit solved the problem but a word of caution. If it is a clean coldfusion install, postParametersLimit is already in the file but further down. I had originally put it right under postsizelimit like instructed with no results. I finally did a search for it in the file and found two instances so the value was getting set back to 100.