USN-612-5: OpenSSH update

14 May 2008

OpenSSH update

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Details

Matt Zimmerman discovered that entries in ~/.ssh/authorized_keys
with options (such as "no-port-forwarding" or forced commands) were
ignored by the new ssh-vulnkey tool introduced in OpenSSH (see
USN-612-2). This could cause some compromised keys not to be
listed in ssh-vulnkey's output.

This update also adds more information to ssh-vulnkey's manual page.

Original advisory details:

A weakness has been discovered in the random number generator used
by OpenSSL on Debian and Ubuntu systems. As a result of this
weakness, certain encryption keys are much more common than they
should be, such that an attacker could guess the key through a
brute-force attack given minimal knowledge of the system. This
particularly affects the use of encryption keys in OpenSSH, OpenVPN
and SSL certificates.

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 8.04
Ubuntu 7.10
Ubuntu 7.04

After performing a standard system upgrade, users are encouraged to
re-run ssh-vulnkey on their systems.

References

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