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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">
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<glsa id="201512-03">
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<title>GRUB: Authentication bypass</title>
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<synopsis>GRUB's authentication prompt can be bypassed by entering a sequence
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of backspace characters.
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</synopsis>
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<product type="ebuild">grub</product>
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<announced>2015-12-19</announced>
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<revised count="1">2015-12-19</revised>
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<bug>568326</bug>
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<access>local</access>
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<affected>
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<package name="sys-boot/grub" auto="no" arch="*">
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<unaffected range="ge">2.02_beta2-r8</unaffected>
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<unaffected range="rge">0.97</unaffected>
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<vulnerable range="lt">2.02_beta2-r8</vulnerable>
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</package>
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</affected>
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<background>
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<p>GNU GRUB is a multiboot boot loader used by most Linux systems.</p>
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</background>
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<description>
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<p>An integer underflow in GRUB’s username/password authentication code
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has been discovered.
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</p>
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</description>
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<impact type="normal">
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<p>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 e.g.
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to get full access to GRUB’s console or to load a customized kernel.
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</p>
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</impact>
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<workaround>
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<p>There is no known workaround at this time.</p>
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</workaround>
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<resolution>
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<p>All GRUB 2.x users should upgrade to the latest version:</p>
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<code>
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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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</code>
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<p>After upgrading, make sure to run the grub2-install command with options
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appropriate for your system. See the GRUB2 Quick Start guide in the
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references below for examples. Your system will be vulnerable until this
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action is performed.
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</p>
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</resolution>
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<references>
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<uri link="https://nvd.nist.gov/nvd.cfm?cvename=CVE-2015-8370">CVE-2015-8370</uri>
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<uri link="https://wiki.gentoo.org/wiki/GRUB2_Quick_Start">GRUB2 Quick
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Start guide
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</uri>
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</references>
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<metadata tag="requester" timestamp="2015-12-19T13:09:44Z">
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keytoaster
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</metadata>
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<metadata tag="submitter" timestamp="2015-12-19T14:20:07Z">
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keytoaster
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</metadata>
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</glsa>
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