USN-6560-2: OpenSSH vulnerabilities
11 January 2024
Several security issues were fixed in OpenSSH.
Releases
Packages
- openssh - secure shell (SSH) for secure access to remote machines
Details
USN-6560-1 fixed several vulnerabilities in OpenSSH. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
Original advisory details:
Fabian Bäumer, Marcus Brinkmann, Jörg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue. (CVE-2023-48795)
It was discovered that OpenSSH incorrectly handled user names or host names
with shell metacharacters. An attacker could possibly use this issue to
perform OS command injection. This only affected Ubuntu 18.04 LTS. (CVE-2023-51385)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04
-
openssh-client
-
1:7.6p1-4ubuntu0.7+esm3
Available with Ubuntu Pro
-
openssh-server
-
1:7.6p1-4ubuntu0.7+esm3
Available with Ubuntu Pro
Ubuntu 16.04
-
openssh-client
-
1:7.2p2-4ubuntu2.10+esm5
Available with Ubuntu Pro
-
openssh-server
-
1:7.2p2-4ubuntu2.10+esm5
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.
References
Related notices
- USN-6560-1: ssh, openssh-sftp-server, openssh-tests, openssh-client, ssh-askpass-gnome, openssh, openssh-server
- USN-6561-1: libssh-dev, libssh-doc, libssh-gcrypt-4, libssh-gcrypt-dev, libssh-4, libssh
- USN-6585-1: libssh2-1-dev, libssh2, libssh2-1
- USN-6589-1: filezilla-common, filezilla
- USN-6598-1: python3-paramiko, paramiko-doc, paramiko
- USN-6738-1: lxd-client, lxd-tools, golang-github-lxc-lxd-dev, lxd, lxc2
- USN-7051-1: python3-asyncssh, python-asyncssh, python-asyncssh-doc
- USN-6565-1: ssh, openssh-sftp-server, openssh-tests, openssh-client, ssh-askpass-gnome, openssh, openssh-server
- USN-6560-3: ssh, openssh-client-ssh1, openssh-sftp-server, openssh-client, ssh-askpass-gnome, ssh-krb5, openssh, openssh-server