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Gentoo Linux Security Advisory GLSA 200710-14 |
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http://security.gentoo.org/ |
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Severity: Normal |
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Title: DenyHosts: Denial of Service |
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Date: October 13, 2007 |
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Bugs: #181213 |
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ID: 200710-14 |
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Synopsis |
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======== |
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|
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DenyHosts does not correctly parse log entries, potentially causing a |
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remote Denial of Service. |
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|
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Background |
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========== |
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|
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DenyHosts is designed to monitor SSH servers for repeated failed login |
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attempts. |
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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 app-admin/denyhosts < 2.6-r1 >= 2.6-r1 |
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|
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Description |
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=========== |
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|
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Daniel B. Cid discovered that DenyHosts used an incomplete regular |
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expression to parse failed login attempts, a different issue than GLSA |
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200701-01. |
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|
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Impact |
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====== |
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|
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A remote unauthenticated attacker can add arbitrary hosts into the |
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blacklist, including the "all" keyword, by submitting specially crafted |
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version identification strings to the SSH server banner. An attacker |
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may use this to prevent legitimate users from accessing a host |
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remotely. |
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|
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Workaround |
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========== |
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|
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There is no known workaround at this time. |
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|
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Resolution |
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========== |
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All DenyHosts users should upgrade to the latest version: |
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|
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# emerge --sync |
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# emerge --ask --oneshot --verbose ">=app-admin/denyhosts-2.6-r1" |
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|
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References |
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========== |
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|
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[ 1 ] CVE-2007-4323 |
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4323 |
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|
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Availability |
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============ |
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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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|
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http://security.gentoo.org/glsa/glsa-200710-14.xml |
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|
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Concerns? |
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========= |
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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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|
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License |
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======= |
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|
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Copyright 2007 Gentoo Foundation, Inc; referenced text |
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belongs to its owner(s). |
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|
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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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-- |
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