A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.
{ "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client-ssh1" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client-ssh1-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-client-udeb-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-server" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-server-udeb-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "ssh" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "ssh-askpass-gnome-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.10+esm7", "binary_name": "ssh-krb5" } ] }
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-hmac" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-ssh1" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-ssh1-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-client-udeb-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-server" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-server-hmac" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-server-udeb-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "ssh" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "ssh-askpass-gnome-dbgsym" }, { "binary_version": "1:7.2p2-4ubuntu2.fips.2.10.7", "binary_name": "ssh-krb5" } ] }
{ "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-client" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-server" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "ssh" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:7.6p1-4ubuntu0.7+esm4", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-client" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-client-hmac" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-server" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-server-hmac" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-tests" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "ssh" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:7.9p1-10~ubuntu18.04.fips.0.10", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-client" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-server" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-tests" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "ssh" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:8.2p1-4ubuntu0.12", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-client" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-client-udeb" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-server" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-server-udeb" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-tests" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "ssh" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:8.2p1-4ubuntu0.fips.0.12", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-client" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-server" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-tests" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "ssh" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:8.9p1-3ubuntu0.11", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-client" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-server" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-tests" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "ssh" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:8.9p1-3ubuntu0.11+Fips1", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-client" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-server" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-tests" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "ssh" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:9.7p1-7ubuntu4.2", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-client" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-client-dbgsym" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-server" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-server-dbgsym" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-sftp-server" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-sftp-server-dbgsym" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-tests" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "openssh-tests-dbgsym" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "ssh" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "ssh-askpass-gnome" }, { "binary_version": "1:9.6p1-3ubuntu13.8", "binary_name": "ssh-askpass-gnome-dbgsym" } ] }