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Gentoo Linux Security Advisory GLSA 201601-01 |
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https://security.gentoo.org/ |
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Severity: Normal |
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Title: OpenSSH: Multiple vulnerabilities |
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Date: January 16, 2016 |
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Bugs: #571892 |
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ID: 201601-01 |
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Synopsis |
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======== |
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|
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Multiple vulnerabilities have been found in OpenSSH, allowing attackers |
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to leak client memory to a server, including private keys. |
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Background |
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========== |
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|
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OpenSSH is a complete SSH protocol implementation that includes SFTP |
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client and server support. |
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|
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Affected packages |
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================= |
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|
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------------------------------------------------------------------- |
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Package / Vulnerable / Unaffected |
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------------------------------------------------------------------- |
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1 net-misc/openssh < 7.1_p2 >= 7.1_p2 |
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Description |
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=========== |
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|
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Qualys have reported two issues in the "roaming" code included in the |
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OpenSSH client, which provides undocumented, experimental support for |
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resuming SSH connections. An OpenSSH client could be tricked into |
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leaking parts of its memory to a malicious server. Furthermore, a |
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buffer overflow can be exploited by a malicious server, but its |
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exploitation requires non-default options and is mitigated due to |
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another bug. |
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|
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Impact |
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====== |
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|
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A remote attacker could entice a user to connect to a specially crafted |
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OpenSSH server, possibly resulting in the disclosure of the user's |
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private keys. Users with private keys that are not protected by a |
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passphrase are advised to generate new keys if they have connected to |
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an SSH server they don't fully trust. |
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|
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Note that no special configuration is required to be vulnerable as the |
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roaming feature is enabled by default on the client. |
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|
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Workaround |
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========== |
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|
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The issues can be worked around by disabling the roaming code. To do |
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so, add "UseRoaming no" to the SSH client configuration, or specify "-o |
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'UseRoaming no'" on the command line. |
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Resolution |
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========== |
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All OpenSSH users should upgrade to the latest version: |
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# emerge --sync |
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# emerge --ask --oneshot --verbose ">=net-misc/openssh-7.1_p2" |
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|
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References |
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========== |
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|
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[ 1 ] CVE-2016-0777 |
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http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0777 |
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[ 2 ] CVE-2016-0778 |
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http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0778 |
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|
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Availability |
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============ |
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This GLSA and any updates to it are available for viewing at |
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the Gentoo Security Website: |
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https://security.gentoo.org/glsa/201601-01 |
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Concerns? |
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========= |
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Security is a primary focus of Gentoo Linux and ensuring the |
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confidentiality and security of our users' machines is of utmost |
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importance to us. Any security concerns should be addressed to |
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security@g.o or alternatively, you may file a bug at |
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https://bugs.gentoo.org. |
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License |
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======= |
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Copyright 2016 Gentoo Foundation, Inc; referenced text |
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belongs to its owner(s). |
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The contents of this document are licensed under the |
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Creative Commons - Attribution / Share Alike license. |
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http://creativecommons.org/licenses/by-sa/2.5 |
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