CVE-2020-14311: Buffer Overflow

Published Jun 29, 2020
·
Updated

A flaw was found in grub2 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32MAX causes an arithmetic overflow, leading to a zero-sized memory allocation with a subsequent heap-based buffer overflow. The highest threat from this vulnerability is to integrity and system availability.

Other sources

Integer overflow in grubext2readlink triggered by a specially crafted ext4 filesystem containing a symlink inode with a size of UINT32MAX, which leads to a zero-sized allocation and subsequent heap buffer overflow with attacker controlled data.

Red Hat

There is an issue with grub2 before version 2.06 while handling symlink on ext filesystems. A filesystem containing a symbolic link with an inode size of UINT32MAX causes an arithmetic overflow leading to a zero-sized memory allocation with subsequent heap-based buffer overflow.

Affected Software

46 affected componentsFixes available
redhat/fwupdate<0:12-6.el7_8
0:12-6.el7_8
redhat/grub2<1:2.02-0.86.el7_8
1:2.02-0.86.el7_8
redhat/shim<0:15-7.el7_9
0:15-7.el7_9
redhat/shim-signed<0:15-7.el7_8
0:15-7.el7_8
redhat/grub2<1:2.02-0.86.el7_2
1:2.02-0.86.el7_2
redhat/shim<0:15-8.el7
0:15-8.el7
redhat/shim-signed<0:15-8.el7_2
0:15-8.el7_2
redhat/grub2<1:2.02-0.86.el7
1:2.02-0.86.el7
redhat/shim-signed<0:15-8.el7_3
0:15-8.el7_3
redhat/fwupdate<0:9-10.el7_4
0:9-10.el7_4
redhat/grub2<1:2.02-0.86.el7_4
1:2.02-0.86.el7_4
redhat/shim-signed<0:15-8.el7_4
0:15-8.el7_4
redhat/fwupdate<0:12-6.el7_6
0:12-6.el7_6
redhat/grub2<1:2.02-0.86.el7_6
1:2.02-0.86.el7_6
redhat/shim-signed<0:15-8.el7_6
0:15-8.el7_6
redhat/fwupdate<0:12-6.el7_7
0:12-6.el7_7
redhat/grub2<1:2.02-0.86.el7_7
1:2.02-0.86.el7_7
redhat/shim-signed<0:15-8.el7_7
0:15-8.el7_7
redhat/fwupd<0:1.1.4-7.el8_2
0:1.1.4-7.el8_2
redhat/grub2<1:2.02-87.el8_2
1:2.02-87.el8_2
redhat/shim<0:15-14.el8_2
0:15-14.el8_2
redhat/shim-unsigned-x64<0:15-7.el8
0:15-7.el8
redhat/fwupd<0:1.1.4-2.el8_0
0:1.1.4-2.el8_0
redhat/grub2<1:2.02-87.el8_0
1:2.02-87.el8_0
redhat/shim<0:15-14.el8_0
0:15-14.el8_0
redhat/fwupd<0:1.1.4-2.el8_1
0:1.1.4-2.el8_1
redhat/grub2<1:2.02-87.el8_1
1:2.02-87.el8_1
redhat/shim<0:15-14.el8_1
0:15-14.el8_1
redhat/grub<2.06
2.06
GNU GRUB2<2.06
redhat Enterprise Linux=7.0
redhat Enterprise Linux=8.0
redhat Enterprise Linux Eus=8.1
redhat Enterprise Linux Eus=8.2
redhat Enterprise Linux Server Aus=8.2
redhat Enterprise Linux Server Tus=8.2
openSUSE Leap=15.1
openSUSE Leap=15.2
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=20.04
Microsoft azl3 grub2 2.06-23
Microsoft cm1 grub2 2.06~rc1-4
Microsoft cbl2 grub2 2.06~rc1-7
debian/grub2
2.06-3~deb11u62.06-13+deb12u12.12-92.14~git20250718.0e36779-22.14-2

Event History

Jul 29, 2020
CVE Published
05:00 PM
Jul 31, 2020
CVE Published
via MITRE·08:56 PM
Data Sourced
via MITRE·08:56 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·10:15 PM
DescriptionSeverityWeaknessAffected Software
Sep 25, 2020
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·07:00 AM
Affected Software
Updated
via Microsoft·07:00 AM
SeverityAffected Software
Updated
via Microsoft·07:00 AM
DescriptionSeverityWeakness
Jan 11, 2024
Data Sourced
via Launchpad·11:40 PM
Description
Feb 24, 2026
Data Sourced
via Ubuntu·06:22 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·06:23 PM
DescriptionAffected Software

Frequently Asked Questions

1

What is CVE-2020-14311?

CVE-2020-14311 is a vulnerability in grub2 that can lead to a heap-based buffer overflow.

2

How severe is CVE-2020-14311?

CVE-2020-14311 has a severity score of 5.7, which is considered medium.

3

Which software is affected by CVE-2020-14311?

grub2 versions before 2.06 and fwupdate versions 0:12-6.el7_8 are affected by CVE-2020-14311.

4

What is the remedy for CVE-2020-14311?

To fix CVE-2020-14311, update grub2 to version 2.06 or fwupdate to version 0:12-6.el7_8.

5

Where can I find more information about CVE-2020-14311?

You can find more information about CVE-2020-14311 at the following references: [link1](https://access.redhat.com/errata/RHSA-2020:3216), [link2](https://access.redhat.com/security/cve/cve-2020-14311), [link3](https://access.redhat.com/errata/RHSA-2020:3217)

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