..  include:: /Includes.rst.txt

==========================
TYPO3 Exception 1588095935
==========================

..  include:: /If-you-encounter-this-exception.rst.txt


TYPO3\\CMS\\Core\\Http\\Security\\MissingReferrerException
==========================================================

..  code-block:: text

    #1588095935 TYPO3\CMS\Core\Http\Security\MissingReferrerException
    Missing referrer for /main

This error occurs when logging into the backend or Install Tool and is
triggered by a failed check of the :code:`Referer` header.

The reason for this may be:

* the use of an HTTP proxy, e.g. a reverse proxy to an encapsulated system without sufficient header delegation
* the webserver is not configured correctly to use a valid certificate

Solution
--------

* Check whether the HTTPS proxy is configured correctly.
* Check whether the values for the variables are correct:

  * `$GLOBALS['TYPO3_CONF_VARS']['SYS']['reverseProxySSL'] <https://docs.typo3.org/permalink/t3coreapi:confval-globals-typo3-conf-vars-sys-reverseproxyssl>`_
  * `$GLOBALS['TYPO3_CONF_VARS']['SYS']['reverseProxyIP'] <https://docs.typo3.org/permalink/t3coreapi:confval-globals-typo3-conf-vars-sys-reverseproxyip>`_
  * `$GLOBALS['TYPO3_CONF_VARS']['SYS']['trustedHostsPattern'] <https://docs.typo3.org/permalink/t3coreapi:confval-globals-typo3-conf-vars-sys-trustedhostspattern>`_

* Check whether the HTTPS connection is secured by a valid certificate.

The security check for the correct referrer was introduced due to potential security risks,
visit the related `security advisory <https://typo3.org/security/advisory/typo3-core-sa-2020-006>`__
for more information.

It is recommended that you keep this feature enabled, but it can be enabled or disabled in
:guilabel:`Admin Tools > Settings > Configure Installation-Wide Options > System > [SYS][features][security.backend.enforceReferrer]`.