6.9 - RHSA-2015:2623

Problem Description:

Updated grub2 packages that fix one security issue and one bug are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Client (v. 7) - x86_64 Red Hat Enterprise Linux Client Optional (v. 7) - x86_64 Red Hat Enterprise Linux ComputeNode (v. 7) - x86_64 Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64 Red Hat Enterprise Linux Server (v. 7) - aarch64, ppc64, ppc64le, x86_64 Red Hat Enterprise Linux Server Optional (v. 7) - aarch64, x86_64 Red Hat Enterprise Linux Workstation (v. 7) - x86_64 Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64

3. Description:

The grub2 packages provide version 2 of the Grand Unified Bootloader (GRUB), a highly configurable and customizable bootloader with modular architecture. The packages support a variety of kernel formats, file systems, computer architectures, and hardware devices.

A flaw was found in the way the grub2 handled backspace characters entered in username and password prompts. An attacker with access to the system console could use this flaw to bypass grub2 password protection and gain administrative access to the system. (CVE-2015-8370)

This update also fixes the following bug:

* When upgrading from Red Hat Enterprise Linux 7.1 and earlier, a configured boot password was not correctly migrated to the newly introduced user.cfg configuration files. This could possibly prevent system administrators from changing grub2 configuration during system boot even if they provided the correct password. This update corrects the password migration script and the incorrectly generated user.cfg file. (BZ#1290089)

All grub2 users are advised to upgrade to these updated packages, which contain backported patches to correct these issues.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

5. Bugs fixed (https://bugzilla.redhat.com/):

1286966 - CVE-2015-8370 grub2: buffer overflow when checking password entered during bootup 1290089 - Grub password broken by update from RHEL7.1 to RHEL7.2