The bencoding parser in BitTorrent uTorrent through 3.5.5 (build 45505) misparses nested bencoded dictionaries, which allows a remote attacker to cause a denial of service.
https://utclient.utorrent.com/offers/beta_release_notes/release_notes.html
https://forum.utorrent.com/forum/13-announcements/
https://blog.whtaguy.com/2020/09/utorrent-cve-2020-8437-vulnerability.html