RHEL 7 : grub2 (RHSA-2015:2623)

high Nessus Plugin ID 87397

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Synopsis

The remote Red Hat host is missing a security update for grub2.

Description

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2015:2623 advisory.

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. For this update to take effect on BIOS-based machines, grub2 needs to be reinstalled as documented in the Reinstalling GRUB 2 on BIOS-Based Machines section of the Red Hat Enterprise Linux 7 System Administrator's Guide linked to in the References section. No manual action is needed on UEFI-based machines.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL grub2 package based on the guidance in RHSA-2015:2623.

Plugin Details

Severity: High

ID: 87397

File Name: redhat-RHSA-2015-2623.nasl

Version: 2.14

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 12/16/2015

Updated: 11/4/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.4

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2015-8370

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.7

Vector: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:grub2-efi, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:redhat:enterprise_linux:grub2-tools, p-cpe:/a:redhat:enterprise_linux:grub2-efi-modules, p-cpe:/a:redhat:enterprise_linux:grub2

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 1/27/2016

Vulnerability Publication Date: 12/16/2015

Reference Information

CVE: CVE-2015-8370

CWE: 787

RHSA: 2015:2623

Detections

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