Duplicate headers received from server

Purvesh Desai picture Purvesh Desai · Nov 27, 2012 · Viewed 113.5k times · Source

Duplicate headers received from server

The response from the server contained duplicate headers. This problem is generally the result of a misconfigured website or proxy. Only the website or proxy administrator can fix this issue.

Error 349 (net::ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION): Multiple distinct Content-Disposition headers received. This is disallowed to protect against HTTP response splitting attacks.

I found this error while exporting to pdf in chrome.

Response.Buffer = false;
Response.ClearHeaders();
string ext = objProp.PACKAGEFILENAME.Substring(objProp.PACKAGEFILENAME.LastIndexOf("."));
string ext1 = ext.Substring(1);
Response.ContentType = ext1;
Response.AddHeader("Content-Disposition", "target;_blank,attachment; filename=" + objProp.PACKAGEFILENAME);
const int ChunkSize = 1024;
byte[] binary = objProp.PACKAGEDOCUMENT;
System.IO.MemoryStream ms = new System.IO.MemoryStream(binary);
int SizeToWrite = ChunkSize;

for (int i = 0; i < binary.GetUpperBound(0) - 1; i = i + ChunkSize)
{
    if (!Response.IsClientConnected) return;
    if (i + ChunkSize >= binary.Length) SizeToWrite = binary.Length - i;
    byte[] chunk = new byte[SizeToWrite];
    ms.Read(chunk, 0, SizeToWrite);
    Response.BinaryWrite(chunk);
    Response.Flush();
}
Response.Close();

How to fix this?

Answer

Bryan Roberts picture Bryan Roberts · Feb 12, 2013

This ones a little old but was high in the google ranking so I thought I would throw in the answer I found from Chrome, pdf display, Duplicate headers received from the server

Basically my problem also was that the filename contained commas. Do a replace on commas to remove them and you should be fine. My function to make a valid filename is below.

    public static string MakeValidFileName(string name)
    {
        string invalidChars = Regex.Escape(new string(System.IO.Path.GetInvalidFileNameChars()));
        string invalidReStr = string.Format(@"[{0}]+", invalidChars);
        string replace = Regex.Replace(name, invalidReStr, "_").Replace(";", "").Replace(",", "");
        return replace;
    }