In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-common" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-common-dbgsym" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-scraping-server" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-scraping-server-dbgsym" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-standalone-server" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-standalone-server-dbgsym" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-viewer" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-viewer-dbgsym" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-xorg-extension" }, { "binary_version": "1.10.1+dfsg-3ubuntu0.20.04.1+esm1", "binary_name": "tigervnc-xorg-extension-dbgsym" } ] }