Causes and countermeasures for logging out of Excel when linking from Excel

When you step on a link from Word or Excel, you are somehow sent to the login screen. Do you have such an experience?Troubleshooting ArticlesI used to have this problem with learningBOX, but I'm not sure what it is.Version 2.8.9If you are having similar problems with other systems than learningBOX, we would like to share the causes and solutions.

Content

• 1. symptoms
• 2. cause
• 2. countermeasures
• 3. why was it discovered in the first place?
• 4. are the web apps of the world coping?

symptoms

When you are logged into a system, if you open a URL in the system from Word or Excel, you will be redirected to the login screen.
Since you are already logged in, we want you to open the URL directly in the system.

cause

In Word or Excel, when you click on a link, Word or Excel sends a request to that link address; Word or Excel receives a response that redirects you to the login page, because you are not logged in to the linked site. The URL for this redirect is passed to the web browser, which causes a transition to the login page.

counter-measure

When a request for the page after login is received from Word or Excel, no redirection processing is performed. By doing this, the specified URL will be passed to the web browser as it is, and the page after login can be opened. In the above figure, you can change the process at ②.

If you are using PHP, you can use the following code to handle the problem, but please follow the style of your framework to terminate the process, because exiting may have side effects. If you return an empty document with status code 200, you should be OK.

How did you find out about it in the first place?

One of our customers is distributing URLs of teaching materials in Excel, and when he steps on the link, he is somehow sent to the login screen. Since there is no special exception for opening from Excel, we investigated the cause of the problem by referring to the web server logs, etc., and found that the problem was caused by strange behavior of Office.

Are the web apps of the world coping?

As of January 14, 2020, Gmail and Slack have been addressed, but there are many services that everyone knows that have not been addressed. This is not a problem with the web application side, but rather a problem with the behavior of Office, which can be easily dealt with using the above method.