[google-chrome] Duplicate headers received from server

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?

The server SHOULD put double quotes around the filename, as mentioned by @cusman and @Touko in their replies.

For example:

Response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");

For me the issue was about a comma not in the filename but as below: -

Response.ok(streamingOutput,MediaType.APPLICATION_OCTET_STREAM_TYPE).header("content-disposition", "attachment, filename=your_file_name").build();

I accidentally put a comma after attachment. Got it resolved by replacing comma with a semicolon.

Double quotes around the filename in the header is the standard per MDN web docs. Omitting the quotes creates multiple opportunities for problems arising from characters in the filename.

Just put a pair of double quotes around your file name like this:

this.Response.AddHeader("Content-disposition", $"attachment; filename=\"{outputFileName}\"");