sudo Heap Overflow Vulnerability (CVE-2021-3156)

Vulnerability Overview

A foreign research team discovered a sudo heap overflow vulnerability (CVE-2021-3156), which had been hidden for a decade. An ordinary user can exploit this vulnerability to gain root privileges on a sudo host with default configuration. Vulnerability details have been publicly disclosed on the internet.

Vulnerability ID

CVE-2021-3156

Comprehensive Vulnerability Rating

High

Vulnerability Scope

All versions from 1.8.2 to 1.8.31p2

All stable versions from 1.9.0 to 1.9.5p1

Fixed Version:

Sudo 1.9.5p2 or later

Vulnerability Impact:

Local privilege escalation

Security Recommendations

Redhat and other Linux distributions have urgently released fix patches. Users are advised to upgrade as soon as possible:

CentOS system users:

1. CentOS 6: Default sudo is within the affected range. CentOS official support has been discontinued;

2. CentOS 7: Upgrade to sudo-1.8.23-10.el7_9.1 or later;

3. CentOS 8: Upgrade to sudo-1.8.29-6.el8_3.1 or later.

Ubuntu system users:

1. Ubuntu 20.04 LTS users are advised to upgrade to the following version:

sudo - 1.8.31-1ubuntu1.2

sudo-ldap - 1.8.31-1ubuntu1.2

2. Ubuntu 18.04 LTS users are advised to upgrade to the following version:

sudo - 1.8.21p2-3ubuntu1.4

sudo-ldap - 1.8.21p2-3ubuntu1.4

3. Ubuntu 16.04 LTS users are advised to upgrade to the following version:

sudo - 1.8.16-0ubuntu1.10

sudo-ldap - 1.8.16-0ubuntu1.10

It is recommended to back up your data before upgrading to avoid any unexpected issues.

Script Function

This bash script is the detection script officially provided by Red Hat!

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