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Gentoo Linux Security Advisory GLSA 200412-01 |
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http://security.gentoo.org/ |
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Severity: Normal |
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Title: rssh, scponly: Unrestricted command execution |
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Date: December 03, 2004 |
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Bugs: #72815, #72816 |
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ID: 200412-01 |
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Synopsis |
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======== |
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|
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rssh and scponly do not filter command-line options that can be |
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exploited to execute any command, thereby allowing a remote user to |
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completely bypass the restricted shell. |
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|
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Background |
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========== |
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|
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rssh and scponly are two restricted shells, allowing only a few |
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predefined commands. They are often used as a complement to OpenSSH to |
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provide access to remote users without providing any remote execution |
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privileges. |
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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/scponly < 4.0 >= 4.0 |
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2 app-shells/rssh <= 2.2.2 Vulnerable! |
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------------------------------------------------------------------- |
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NOTE: Certain packages are still vulnerable. Users should migrate |
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to another package if one is available or wait for the |
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existing packages to be marked stable by their |
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architecture maintainers. |
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------------------------------------------------------------------- |
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2 affected packages on all of their supported architectures. |
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------------------------------------------------------------------- |
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|
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Description |
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=========== |
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|
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Jason Wies discovered that when receiving an authorized command from an |
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authorized user, rssh and scponly do not filter command-line options |
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that can be used to execute any command on the target host. |
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|
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Impact |
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====== |
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|
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Using a malicious command, it is possible for a remote authenticated |
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user to execute any command (or upload and execute any file) on the |
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target machine with user rights, effectively bypassing any restriction |
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of scponly or rssh. |
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Workaround |
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========== |
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There is no known workaround at this time. |
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Resolution |
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========== |
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All scponly users should upgrade to the latest version: |
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# emerge --sync |
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# emerge --ask --oneshot --verbose ">=net-misc/scponly-4.0" |
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Currently, there is no released version of rssh that contains a fix for |
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these issues. The author declared that he cannot provide a fixed |
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version at this time. Therefore, the rssh package has been hard-masked |
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prior to complete removal from Portage, and current users are advised |
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to unmerge the package. |
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|
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References |
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========== |
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[ 1 ] BugTraq Posting |
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http://www.securityfocus.com/archive/1/383046/2004-11-30/2004-12-06/0 |
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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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http://security.gentoo.org/glsa/glsa-200412-01.xml |
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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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http://bugs.gentoo.org. |
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License |
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======= |
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Copyright 2004 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/2.0 |
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