Microsoft Teams Incoming Webhook Button \w File-Link

Question

I'm sending a message to a Microsoft Teams channel using incoming webhooks. This works perfectly fine except for the button "Open log" which should open a file via the browser but simply doesn't.

JSON

{
    "@type": "MessageCard",
    "@context": "http://schema.org/extensions",
    "themeColor": "0076D7",
    "summary": "Error Log",
    "sections": [{
        "activityTitle": "Error in integration " + integration_name,
        "activitySubtitle": "live stage",
        "markdown": True,
        "text": message
    }],
    "potentialAction": [{
        "@type": "ActionCard",
        "name": "Open log",
        "actions": [{
            "@type": "OpenUri",
            "name": "Open log",
            "targets": [{
                "os": "default",
                "uri": "file://someserver/d$/somefolder/logs/" + logname
            }]
        }]
    }]
}

The result of this webhook call looks like this: Message via webhook

My problem is, that this button does absolutely nothing. If I use standard websites, even android/iOS URLs, it works like expected.

Any help to solve this is much appreciated! Am I doing something wrong? Is Microsoft Teams blocking file:// links?

Bill Bliss - MSFT Bill Bliss - MSFT · Accepted Answer · 2018-06-20T02:57:45

Yes, currently we sanitize (block) file:// links as they are a pretty significant security hole (e.g. local executables/batch files). See here for more info.

That said, your use case seems both valid and safe. How would you like it to work while still being secure?

Microsoft Teams Incoming Webhook Button \w File-Link

2 Answers