We could have pwned Microsoft Teams with a GIF, claims Israeli infosec outfit

A vulnerability existed in Microsoft’s Slack for Suits tool, Teams, that could have let a remote attacker take over accounts by simply sending a malicious GIF, infosec researchers claim.

The pwn-with-GIF vuln was possible, said Cyberark, thanks to two compromisable Microsoft subdomains along with a carefully crafted animated image file.

Although it was a responsibly disclosed theoretical vuln, and was not abused in the wild as far as is known, it illustrates that not all online collaboration platforms are as secure as one might hope.

“Even if an attacker doesn’t gather much information from a Teams’ account, they could use the account to traverse throughout an organization (just like a worm),” mused Cyberark researcher Omer Tsarfati.

The Israeli infosec outfit said it had alerted Redmond to the two subdomains, resulting in their DNS entries being tweaked. The rest of the Teams vuln was patched last Monday, 20 April.

Source: We could have pwned Microsoft Teams with a GIF, claims Israeli infosec outfit • The Register