Gentoo: GLSA-201601-01: OpenSSH: Multiple vulnerabilities
Summary
Qualys have reported two issues in the "roaming" code included in the OpenSSH client, which provides undocumented, experimental support for resuming SSH connections. An OpenSSH client could be tricked into leaking parts of its memory to a malicious server. Furthermore, a buffer overflow can be exploited by a malicious server, but its exploitation requires non-default options and is mitigated due to another bug.
Resolution
All OpenSSH users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/openssh-7.1_p2"
References
[ 1 ] CVE-2016-0777 http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0777 [ 2 ] CVE-2016-0778 http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0778
Availability
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:
https://security.gentoo.org/glsa/201601-01
Concerns
Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users' machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.
Synopsis
Multiple vulnerabilities have been found in OpenSSH, allowing attackersto leak client memory to a server, including private keys.
Background
OpenSSH is a complete SSH protocol implementation that includes SFTP client and server support.
Affected Packages
------------------------------------------------------------------- Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 net-misc/openssh < 7.1_p2 >= 7.1_p2
Impact
=====
A remote attacker could entice a user to connect to a specially crafted
OpenSSH server, possibly resulting in the disclosure of the user's
private keys. Users with private keys that are not protected by a
passphrase are advised to generate new keys if they have connected to
an SSH server they don't fully trust.
Note that no special configuration is required to be vulnerable as the
roaming feature is enabled by default on the client.
Workaround
The issues can be worked around by disabling the roaming code. To do so, add "UseRoaming no" to the SSH client configuration, or specify "-o 'UseRoaming no'" on the command line.
