The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server. Starting with version 3.0.0 and prior to version 3.7.0, by trusting that the server will return a certificate that belongs to the keypair of the user, a malicious server could get the desktop client to encrypt files with a key known to the attacker. This issue is fixed in Nextcloud Desktop 3.7.0. No known workarounds are available.
In versions 3.0.0-3.5.0, 2.0.0-2.9.0, and 1.0.1, when users run the command displayed in NGINX Controller user interface (UI) to fetch the agent installer, the server TLS certificate is not verified.
When importing a revoked key that specified key compromise as the revocation reason, Thunderbird did not update the existing copy of the key that was not yet revoked, and the existing key was kept as non-revoked. Revocation statements that used another revocation reason, or that didn't specify a revocation reason, were unaffected. This vulnerability affects Thunderbird < 91.8.