NAME
    Plack::Middleware::BlockHeaderInjection - block header injections in
    responses

SYNOPSIS
      use Plack::Builder;

      my $app = ...

      $app = builder {
        enable 'BlockHeaderInjection',
          status => 500;
        $app;
      };

DESCRIPTION
    This middleware will check responses for injected headers. If the
    headers contain newlines, then the return code is set to `500' and the
    offending header(s) are removed.

    A common source of header injections is when parameters are passed
    unchecked into a header (such as the redirection location).

    An attacker can use injected headers to bypass system security, by
    forging a header used for security (such as a referrer or cookie).

OPTIONS
  `status'
    The status code to return if an invalid header is found. By default,
    this is `500'.

SEE ALSO
    https://en.wikipedia.org/wiki/HTTP_header_injection

AUTHOR
    Robert Rothenberg, `<rrwo at cpan.org>'

ACKNOWLEDGEMENTS
    Foxtons, Ltd.

LICENSE AND COPYRIGHT
    Copyright 2014 Robert Rothenberg.

    This program is free software; you can redistribute it and/or modify it
    under the terms of the the Artistic License (2.0). You may obtain a copy
    of the full license at:

    http://www.perlfoundation.org/artistic_license_2_0