An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack."
{
"binaries": [
{
"binary_name": "libruby2.3",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm1"
},
{
"binary_name": "ruby2.3",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm1"
},
{
"binary_name": "ruby2.3-dev",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm1"
},
{
"binary_name": "ruby2.3-tcltk",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm1"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}