Updated Sudo packages has been released for Ubuntu 12.04 ESM and 14.04 ESM.

USN-4705-2: Sudo vulnerability

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Ubuntu Security Notice USN-4705-2
January 27, 2021

sudo vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 ESM
- Ubuntu 12.04 ESM

Summary:

Several security issues were fixed in Sudo.

Software Description:
- sudo: Provide limited super user privileges to specific users

Details:

USN-4705-1 fixed a vulnerability in Sudo. This update provides
the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.

Original advisory details:

It was discovered that Sudo incorrectly handled memory when parsing command
lines. A local attacker could possibly use this issue to obtain unintended
access to the administrator account. (CVE-2021-3156)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 14.04 ESM:
sudo 1.8.9p5-1ubuntu1.5+esm6

Ubuntu 12.04 ESM:
sudo 1.8.3p1-1ubuntu3.10

In general, a standard system update will make all the necessary changes.

References:
https://usn.ubuntu.com/4705-2
https://usn.ubuntu.com/4705-1
CVE-2021-3156