On January 26, 2021, a vulnerability in all versions of the sudo software was announced by Qualys.
The Qualys Research Team has discovered a heap overflow vulnerability in sudo, a near-ubiquitous utility available on major Unix-like operating systems. An unprivileged user can gain root privileges on a vulnerable host using a default sudo configuration by exploiting this vulnerability.
Updates have been released for this package to address the issue.
For RPM based systems, run the following command to verify if the RPM on your server is patched:
rpm -q --changelog sudo | grep CVE-2021-3156
You should see output such as:
-bash-4.2# rpm -q --changelog sudo | grep CVE-2021-3156
If there is no output, please follow this guide to update:
Please note that this update does not apply to CentOS 6, as CentOS no longer supports version 6. More information on this is available here: CentOS 6 - End of Life Notice
For Ubuntu, you can check with this command:
zgrep -E 'CVE-2021-3156' /usr/share/doc/sudo/changelog.Debian.gz