Executive Summary

Summary
Title GRUB: Authentication bypass
Informations
Name GLSA-201512-03 First vendor Publication 2015-12-19
Vendor Gentoo Last vendor Modification 2015-12-19
Severity (Vendor) Normal Revision N/A

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
 
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:M/Au:N/C:C/I:C/A:C)
Cvss Base Score 6.9 Attack Range Local
Cvss Impact Score 10 Attack Complexity Medium
Cvss Expoit Score 3.4 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

Synopsis

GRUB's authentication prompt can be bypassed by entering a sequence of backspace characters.

Background

GNU GRUB is a multiboot boot loader used by most Linux systems.

Description

An integer underflow in GRUB's username/password authentication code has been discovered.

Impact

An attacker with access to the system console may bypass the username prompt by entering a sequence of backspace characters, allowing them e.g. to get full access to GRUB's console or to load a customized kernel.

Workaround

There is no known workaround at this time.

Resolution

All GRUB 2.x users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-boot/grub-2.02_beta2-r8"

After upgrading, make sure to run the grub2-install command with options appropriate for your system. See the GRUB2 Quick Start guide in the references below for examples. Your system will be vulnerable until this action is performed.

References

[ 1 ] CVE-2015-8370 : http://nvd.nist.gov/nvd.cfm?cvename=CVE-2015-8370
[ 2 ] GRUB2 Quick Start guide https://wiki.gentoo.org/wiki/GRUB2_Quick_Start

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website:

https://security.gentoo.org/glsa/201512-03

Original Source

Url : http://security.gentoo.org/glsa/glsa-201512-03.xml

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-264 Permissions, Privileges, and Access Controls

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 5
Os 1

Nessus® Vulnerability Scanner

Date Description
2018-08-17 Name : The remote PhotonOS host is missing multiple security updates.
File : PhotonOS_PHSA-2016-0012.nasl - Type : ACT_GATHER_INFO
2016-03-04 Name : The remote Fedora host is missing a security update.
File : fedora_2015-cebe5133e7.nasl - Type : ACT_GATHER_INFO
2016-03-04 Name : The remote Fedora host is missing a security update.
File : fedora_2015-90c27b6e91.nasl - Type : ACT_GATHER_INFO
2016-01-20 Name : The remote Solaris system is missing a security patch from CPU jan2016.
File : solaris_jan2016_SRU11_3_4_5_0.nasl - Type : ACT_GATHER_INFO
2016-01-14 Name : The remote device is missing a vendor-supplied security patch.
File : f5_bigip_SOL25901386.nasl - Type : ACT_GATHER_INFO
2016-01-07 Name : The remote openSUSE host is missing a security update.
File : openSUSE-2016-10.nasl - Type : ACT_GATHER_INFO
2016-01-04 Name : The remote SUSE host is missing one or more security updates.
File : suse_SU-2015-2399-1.nasl - Type : ACT_GATHER_INFO
2015-12-30 Name : The remote SUSE host is missing one or more security updates.
File : suse_SU-2015-2385-1.nasl - Type : ACT_GATHER_INFO
2015-12-30 Name : The remote SUSE host is missing one or more security updates.
File : suse_SU-2015-2387-1.nasl - Type : ACT_GATHER_INFO
2015-12-30 Name : The remote SUSE host is missing one or more security updates.
File : suse_SU-2015-2386-1.nasl - Type : ACT_GATHER_INFO
2015-12-29 Name : The remote openSUSE host is missing a security update.
File : openSUSE-2015-957.nasl - Type : ACT_GATHER_INFO
2015-12-22 Name : The remote Scientific Linux host is missing one or more security updates.
File : sl_20151215_grub2_on_SL7_x.nasl - Type : ACT_GATHER_INFO
2015-12-21 Name : The remote Gentoo host is missing one or more security-related patches.
File : gentoo_GLSA-201512-03.nasl - Type : ACT_GATHER_INFO
2015-12-18 Name : The remote Slackware host is missing a security update.
File : Slackware_SSA_2015-351-01.nasl - Type : ACT_GATHER_INFO
2015-12-17 Name : The remote Debian host is missing a security-related update.
File : debian_DSA-3421.nasl - Type : ACT_GATHER_INFO
2015-12-17 Name : The remote CentOS host is missing one or more security updates.
File : centos_RHSA-2015-2623.nasl - Type : ACT_GATHER_INFO
2015-12-16 Name : The remote Ubuntu host is missing a security-related patch.
File : ubuntu_USN-2836-1.nasl - Type : ACT_GATHER_INFO
2015-12-16 Name : The remote Red Hat host is missing one or more security updates.
File : redhat-RHSA-2015-2623.nasl - Type : ACT_GATHER_INFO
2015-12-16 Name : The remote Oracle Linux host is missing one or more security updates.
File : oraclelinux_ELSA-2015-2623.nasl - Type : ACT_GATHER_INFO
2015-12-14 Name : The remote Debian host is missing a security update.
File : debian_DLA-368.nasl - Type : ACT_GATHER_INFO

Alert History

If you want to see full details history, please login or register.
0
1
2
Date Informations
2016-01-22 09:26:19
  • Multiple Updates
2015-12-22 13:25:33
  • Multiple Updates
2015-12-19 21:22:55
  • First insertion