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Gentoo Linux Security Advisory GLSA 201512-03 |
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https://security.gentoo.org/ |
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Severity: Normal |
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Title: GRUB: Authentication bypass |
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Date: December 19, 2015 |
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Bugs: #568326 |
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ID: 201512-03 |
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Synopsis |
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======== |
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|
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GRUB's authentication prompt can be bypassed by entering a sequence of |
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backspace characters. |
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Background |
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========== |
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|
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GNU GRUB is a multiboot boot loader used by most Linux systems. |
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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 sys-boot/grub < 2.02_beta2-r8 *>= 0.97 * |
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>= 2.02_beta2-r8 * |
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------------------------------------------------------------------- |
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NOTE: Packages marked with asterisks require manual intervention! |
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|
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Description |
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=========== |
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|
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An integer underflow in GRUB's username/password authentication code |
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has been discovered. |
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Impact |
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====== |
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|
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An attacker with access to the system console may bypass the username |
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prompt by entering a sequence of backspace characters, allowing them |
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e.g. to get full access to GRUB's console or to load a customized |
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kernel. |
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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 GRUB 2.x users should upgrade to the latest version: |
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# emerge --sync |
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# emerge --ask --oneshot --verbose ">=sys-boot/grub-2.02_beta2-r8" |
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After upgrading, make sure to run the grub2-install command with |
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options appropriate for your system. See the GRUB2 Quick Start guide in |
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the references below for examples. Your system will be vulnerable until |
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this action is performed. |
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|
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References |
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========== |
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|
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[ 1 ] CVE-2015-8370 |
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http://nvd.nist.gov/nvd.cfm?cvename=CVE-2015-8370 |
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[ 2 ] GRUB2 Quick Start guide |
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https://wiki.gentoo.org/wiki/GRUB2_Quick_Start |
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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/201512-03 |
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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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|
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License |
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======= |
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Copyright 2015 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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