Opening .ics file from local drive causes security notice?

Question

We have been using ics file for years to allow users to download ics file and save to calendar. Download and save still works fine, but opening from saved location triggers Outllook/Office securty dialog box stating the the location may be unsafe. Continue, Yes/No choice included. This stops thousands of our Enterprise users from adding to calendar in the usual way. Various PC's tested, but does not seem to be an issue and the handful of MACS in the company of approximatelym130,000 employees. This was fine four days ago but just popped up yesterday - 1/5/2024.

Answer 1

Is the behavior regarding .ics files "by design" or is it expected to be fixed in near feature?

the sugested resolution in https://support.microsoft.com/en-us/office/outlook-blocks-opening-ics-files-after-installing-protections-for-microsoft-outlook-information-disclosure-vulnerability-released-dec-12-2023-df8647ef-1828-421b-a266-79120b6190bd doesnt seem a good idea as it would expose the user to threads other than .ics files

regards

Per

Answer 2

Looks related to patch for CVE-2023-35636 - Security Update Guide - Microsoft - Microsoft Outlook Information Disclosure Vulnerability

When I uninstall the December update from 2016 for example, it reverts to no longer giving this extra security prompt.

Answer 3

Please pass this along to the people making these decisions that neutering user interface under the guise of security is a weak excuse of a mitigation tactic.

All it takes is enough people to unplug from Microsoft for it to be taken out. It won't be easy, but you piss off enough people, it can be done.

Answer 4

We are also experiencing this issue. However I just want to point out that the dialogs shown (as shown in Tim's reply) are displayed application modal in Outlook and, if the Outlook window is behind another window when opening the .ics file, users don't see any message. It just looks like nothing happens. Whether the message is correct or not, the presentation is appalling.

Answer 5

It was bad enough that we got an initial warning when adding .ics files to my calendar

"Add this Internet Calendar to Outlook?

you should only open calendars from sources you know and trust"

but now we are getting the new popup as well stating that

"This Location may be unsafe...."

I don't need ANY warnings when I do this several times a day it REALLY slows me down!!

Please remove both warnings or provide me a way to remove them