Request Validation - Preventing Script Attacks?
Jan 21, 2010
When a user presses Button1 on the Webpage, I would like to copy slightly modified string from txt1 (Text) into txt2 (Text).
The problem is sometimes I get an error "a potentially dangerous request.form value was detected from the client validaterequest". I get this error when special symbols llike "<" or ">" are in txt1.Text.I've read about that problem. That error is to prevent from hackers who can input scripts into the txt1.All I did is:
1) Put validateRequest="false" into <%@ Page Language="VB" validateRequest="false" at Default.aspx.
2) Default.aspx.vb contains now:
sHTMLEncodedString = Server.HtmlEncode(txt1.Text))
[code]....
Now it works and allows to take any data from txt1, slightly modify it and put into txt2.So, my question is: Did a level of security was reduced after I wrote validateRequest="false" ? Any code should be added to keep the good level of security? Or, I'd better use another way to copy txt1 to txt2?
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Jan 2, 2011
I have a GridView and I need update some data inserting HTML CODE; I would need this data been stored encoded and decoded on request.
I cannot in any way disable globally "Request Validation" and not even at Page Level, so I would need a solution to disable "Request Validation" at Control Level.
At the moment I am using a script which should Html.Encode every value being update, butt seems that "Request Validation" start its job before event RowUpdating, so I get the Error "Page A potentially dangerous Request.Form ... ".
void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
foreach (DictionaryEntry entry in e.NewValues)
{
e.NewValues[entry.Key] = Server.HtmlEncode(entry.Value.ToString());
}
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