Gandalf_The_Grey
Level 76
Thread author
Verified
Honorary Member
Top Poster
Content Creator
Well-known
- Apr 24, 2016
- 6,506
Zoom is a video conferencing platform that has gained popularity throughout the pandemic. Unlike other video conferencing systems that I have investigated, where one user initiates a call that other users must immediately accept or reject, Zoom calls are typically scheduled in advance and joined via an email invitation. In the past, I hadn’t prioritized reviewing Zoom because I believed that any attack against a Zoom client would require multiple clicks from a user. However, a zero-click attack against the Windows Zoom client was recently revealed at Pwn2Own, showing that it does indeed have a fully remote attack surface. The following post details my investigation into Zoom.
This analysis resulted in two vulnerabilities being reported to Zoom. One was a buffer overflow that affected both Zoom clients and MMR servers, and one was an info leak that is only useful to attackers on MMR servers. Both of these vulnerabilities were fixed on November 24, 2021.