I'm intermittently seeing this exception being thrown:
A potentially dangerous Request.QueryString value detected
However when I look in the IIS logs I can see that the request that failed has no querystring logged against it.
How could this be? Are "dangerous" query strings being stripped from the log or something?
I have an ashx handler that was working fine in VS2008 but when I upgraded to VS2010 (haven't gone back to VS2008 to double check though) and when I try to grab the value from HttpContext.Request.Params["update"] I get the following error:
+ ex {"A potentially dangerous Request.QueryString value was detected from the client (update="<SETIProducts><Produ...")."}
System.Exception {System.Web.HttpRequestValidationException}
On a windows 2008 web server, I get the following error whenever posting a form containing html tags in textboxes:
A potentially dangerous Request.Form value was detected from the client (widget$txtText="
This is a common error and you fix it by either doing Page ValidateRequest = false or in the web.config with pages validaterequest = false. However, on this specific server, it completely ignores the validaterequest = false and throws this exception anyway. Has anyone seen this behavior before and know what else I can do to prevent this error? I've seen it in 2 web apps now on the same server, it's really weird.
I have contact form on my website - but when somebody write html tags in this form or any other form he sees error website:
A potentially dangerous Request.Form value was detected in ASP.NET MVC
On this site:
http://www.coderjournal.com/2009/02/potentially-dangerous-requestform-detected-aspnet-mvc/
somebody writes that we should use [Code]....
[Code]....
[Code]....
I am Getting this error
A potentially dangerous Request.Form value was detected from the client (ctl00$ContentPlaceHolder1$txtEmbed="<embed src='http://a...").
when i am opening a modalpopup extender on link button click and in code behind i am assigning the textbox
value="<embed src='http://auddia.com/player-viral.swf' height='20' width='200' allowscriptaccess='always' flashvars='volume=100&autostart=false&file=http://auddia.com/Audios/audioStream_1299222864888_19.flv&plugins=viral-1d'/>
and also i set the ValidateRequest="false" in the page directive's. and in code behind i also use HttpUtility.HtmlEncode . but again and again i am facing this error
"A potentially dangerous Request.Form value was detected from the client (ctl00$ContentPlaceHolder1$txtEmbed="<embed src='http://a...").".
I have one asp.net application, which has some problems while i am entering the special characters such as ": &#, " in the search box. If i enter this text in search box, i got the exception like this. A potentially dangerous Request.Form value was detected from the client (txtValue=": &#, ").
then i searched on the net, i got one general solution for this that to set the validaterequest to false. But no changes has been made on my application.
[Update : I have inserted this post in "XML Web Services" section by mistake, so if you are a moderator or Admin, please shift it to "Security" section or any other relevant section]
I am working with WCF REST Service Application in .Net 4.0 and my service is hosted on II7 (Windows 7 Ultimate - 64 bit).My service and all other code is working completely fine.But when I use the '&' character in request url, it shows the following Error.I have already tried adding following section in my web.config as shown here on www.asp.net
<system.web>
I am using Webhandler to upload images to the server. I want to send the folder name so on that folder the images will save. I am using this URI format and got the below error.
builder.Path = builder.Path.TrimEnd('/')
+ "/Services/FileReceiver.ashx?foldername=" +
folder;
this.Uri
= builder.Uri;
Also I added the following line in the web.config but still having the issue.
<httpRuntime requestValidationMode="2.0" />
A potentially dangerous Request.Path value was detected from the client (?). Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.HttpException: A potentially dangerous Request.Path value was detected from the client (?).
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack
Trace:
[HttpException (0x80004005): A potentially dangerous Request.Path value was detected from the client (?).]
System.Web.HttpRequest.ValidateInputIfRequiredByConfig() +8884233
System.Web.ValidateRequestExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +35
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184
Version
Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1
I have a form that a user fills out and can input html or other text into a textarea. I have the validaterequest attribute set to false on the page. However, when I submit the form with any html characters it bombs saying that it detected the potentially dangerous request field and to make validaterequest=false. I've already done this so I'm not sure why it's not working. I've done this many times before and never had this problem. Anyone run into this before and if so, is there a fix? I don't want to update my web.config and apply it site wide.
View 1 RepliesI'm using a php script to http post some xml files to a .net URL.
When I submit I get the response:
A potentially dangerous Request.Form
value was detected from the client
(<?xml version="...UTF-8"?> <!DOCTYPE
cXML SYSTE...").
Description: Request Validation has detected a potentially dangerous client input value, and
processing of the request has been aborted. This value may indicate an attempt to compromise the security of your application, such as a cross-site scripting attack. You can disable request validation by setting validateRequest=false in the Page directive or in the configuration section. However, it is strongly recommended that your application explicitly check all inputs in this case.
As I'm not using .NET I can't set ValidateRequest="false" in web.config.
Do I need to sanitize my xml before submitiing? How can I do this?
I know the < and > characters will cause this error, but what other characters/inputs will cause this error?
I'm testing for this error in the Global.asax, and reridrecting to an error page where I want to list all possible values which cause this error, so the user can go back to their page and get rid of them.
I've done some googling, but all I see so far are the < and > characters...surely there are more out there.
To prevent my application from crashing with the error "A potentially dangerous Request.Form value was detected...", I just turned page validation off. I want to revisit this and solve it correctly. Is there a good strategy for this? If people are entering '<' and '>', I think the only way to save their data is to encode it via Javacript. I have tried catching it in the code-behind, but it becomes too late. I am thinking of inheriting the textbox and auto encode/decode the input with client scripts. I also have to think of all the angle brackets that are already saved in my database.
View 4 RepliesEncrypt request.querystring and Descrpt request.querystring
View 1 Replies(probably a bot) sent a request with the following URL to my ASP.NET 4.0 web forms application (running on IIS 7.0):http://ipaddress-of-my-applications-domain/bla1.bla2.bla3.bla4.bla5:)This caused an System.Web.HttpException. I received a logging email from ASP.NET HealthMonitoring I had configured, telling me:A potentially dangerous Request.Path value was detected from the client (:).
System.Web.HttpRequest.ValidateInputIfRequiredByConfig()
System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context)
Why is a colon in the URL "potentially dangerous"? What dangerous things can be done with such a URL? Do I have any security hole here I am not aware of?
In the load event of a web user control I have the following code which I am using to call a function in order to populate a HTML Text Area.The page hosting the control loads fine the first time it loads but on postback it throws the error
Quote:System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client
I have seen people suggest <%@ Page ... validateRequest="false" %>
Firstly I would like to handle this at control level rather than on the hosting page .
Code:
if (!Page.ClientScript.IsStartupScriptRegistered("AddText"))
{
Page.ClientScript.RegisterStartupScript [code]....
I'm writing a product management system for a website. As an administrator defines product details, those details are stored in the Session so that fields remain populated as the user navigates across multiple pages. One of these fields is a "RichTextBox" that allows the user to define a product description with rich text.
Attempting to pack the contents of this rich text box into a Session variable raises the following Server Error:
A potentially dangerous Request.Form value was detected from the client (ctl00_ContentPlaceHolder1_RichTextBox1_tbxRichContent="<b>asdf</b>").
The offending line of code is as follows:
Session["NewProductDescription"] = HttpUtility.HtmlEncode(RichTextBox1.Text);
I thought HtmlEncoding would solve the problem, but it did not.
I have aproblem that when i add some special character in the textbox and submit the page it give error. A potentially dangerous Request.Form value was detected from the client (ctl00$ContentPlaceHolder1$txtname="<test>"). I found the solution of this porblem by ValidateRequest="false". But if i do this then the request will not be validate and then attacks probablity will be increase. what should i do to for this whithout using ValidateRequest attribute.
View 4 RepliesI have an app that was originally running fine in ASP.Net 3.5, using the ValidateRequest set to false to allow HTML to be saved from a rich text box. However, after converting the app to 4.0, I am getting the Potentially Dangerous message, even though both the page and web.config have the value set to false.
I went into the page and created a PagesSection object and checked its value and then set the value to false. Everytime the page is hit (postback or new) the value is always returned as true, until I set it to false. Not sure why it is reverting to true.
I'm testing a Tiny_MCE plugin for BlogEngine.NET extension I wrote earlier and I keep receiving the following error message whenever I use my own extension or the extremely popular SyntaxHighlighter extension which both have similar behaviors and both implement Tiny_MCE plugins:
Url :
'http://localhost/admin/Pages/Add_entry.aspx'
Raw Url : /admin/Pages/Add_entry.aspx[code]...
My question is thus: although I receive this error on my local environment (IIS 7.5 ASP.NET 4.0 Integrated App Pool) I receive no error whatsoever on my live environment (IIS 7.5 ASP.NET 3.5 SP1/ 3.0 / 2.0.) Additionally whenever I test the extension using debug mode in Visual Studio 2010 and run the site off of a separate instance I don't receive this error.I'm almost certain that the fact that this issue only occurs on my localhost IIS instance indicates that it's a configuration issue or a behavior specific to ASP.NET 4.0, but I don't know what exactly.
I am writing a database to store code extracts which will make our life easier at work, I have a text box which retrieves HTML characters, I have no problems in displaying them, however if I click the edit button to amend text I get the error "A potentially danger Request.Form value was detected from the client (txtCodeExtract=" etc").
I have added ValidateRequest="False" to the main form however, when I now click the edit button the textbox wipes out all the text.
I have tried using the Server.HTMLEncode(txtCodeExtracts.Text); or Decode and HttpUtility.HTMLEncode or Decode but the textbox still clears.
This is a web app using Visual Studio 2008
We're trying to implement functionality that intercepts, inspects, and alters if needed data in the Request.QueryString and Request.Form collections.
Since Request.QueryString and Request.Form are readonly, is it possible to use a HttpModule to do this without Reflection or Response.Redirect?
We're thinking that we can construct a new HttpRequest, and replace the original one. Would there be any implications in doing this?
I know mocking this object is impossible without using HttpRequestWrapper, but wasn't sure whether ASP.NET sets other things beyond the constructor.
How can i use querystring for this-
Here in below code i have used querystring for sending imagename from this page to another page. Now i just want that with this imagename in also want to send span element's text with same querystring.How can i achieve this?
[Code]....
The following code works well as long as I pass a querystring value to the datalist.
Private Sub BindGrid()
Dim id As Integer = Integer.Parse(Context.Request.QueryString("id"))
Dim strConnString As String = ConfigurationManager.ConnectionStrings("Conn").ConnectionString
Using con As New SqlConnection(strConnString)
Using cmd As New SqlCommand()
cmd.CommandText = "select Id, Name from tblFiles where Id=@Id"
[Code] ......
However, the page errors with the message "Value cannot be null." if I don't pass a value. I know that DataList does not have an EmptyItem Property like a Gridview control. I do not want the page to error if I don't pass a value. Need info to deal with empty values in a datalist.
Most websites have pointed me to this code to use:
<FooterTemplate>
<asp:Label ID="lblEmpty" Text="No Result" runat="server"
Visible='<%#boolean.parse(([b]list[/b].Items.Count=0).ToString())%>'>
</asp:Label>
</FooterTemplate>
The 'list' throws an error. The error is "Too few type arguments to 'System.COllections.Generic.List". I am not sure if the code is written in C# and that is what is causing the error. It seems that it should work but I can not figure out the 'list' error.
I have a page that I wish to pass an ID in a querystring to another page
eg
Response.Redirect("~/Account/Login.aspx?CertificateID="+ CertificateTextBox.Text);
but the value in the CertificateTextBox is in the format of Encoding.UTF8
so it can contains character like "ZnbiS69F2g22OeupHw+Xlg=="
When the receiving page gets the QueryString
CertificateTextBox.Text = Request.QueryString["CertificateID"];
the "+" and possible other querystring chars like "?" are stripped!!
so I end up with
Request.QueryString["CertificateID"];
returning
"ZnbiS69F2g22OeupHw Xlg=="
the "+" strinpped!
Is there a way to encode these chars so they are not striped by QuesryString()or do I have to use a session variable??
In aspx I have a querystring - www.mysite.com/enter.aspx?dest=#. When I click "enter" I go to main.aspx. I want to get this "?dest=#" in main.aspx with a request.querystring or something in javascript. I need to use the querystring in javascript in main.aspx for another action.
let me explain in detail - I have enter.aspx page that shall load with a querystring - www.mysite.com/enter.aspx?dest=#. Now when i click the Enter button on Enter.aspx page, it shall goto Main.aspx page. When main.aspx page loads i want to write small javascript in main.aspx that shall get the querystring from the previous enter.aspx page and give it an if condition. so if (request.querystring('dest=') > 0 window.open ('a1.jpg') this above code needs to be redesigned so it can work. how can i do this. i tried window.location.href.indexof('dest') , nothing happened.