Wormable exploit found in Microsoft Teams

Security researcher Oskars Vegeris has revealed a wormable exploit for Microsoft Teams, which would exploit the chat client by only viewing a message, without any user interaction.

The result is a “complete loss of confidentiality and integrity for end-users — access to private chats, files, internal network, private keys and personal data outside MS Teams,” Vegeris said.

By exploiting another cross-site scripting (XSS) flaw present in the Teams ‘@mentions’ functionality and a JavaScript-based RCE payload, the code can also be spread to other users of the Teams app, making for a self-spreading exploit.

The exploit is also cross-platform, affecting Windows, Mac, Linux and even the web app.

Fortunately for Teams users, Vegeris discovered the flaw in August, and Microsoft released a patch not long after at the end of October 2020.

Vegeris had also earlier disclosed a critical “wormable” flaw in Slack’s desktop version that could have allowed an attacker to take over the system by simply sending a malicious file to another Slack user.

via Thehackernews