A Mailman security update has been released for Ubuntu Linux 16.04 ESM and 18.04 LTS.

USN-5151-1: Mailman vulnerabilities

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Ubuntu Security Notice USN-5151-1
November 18, 2021

mailman vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in Mailman.

Software Description:
- mailman: Web-based mailing list manager

Details:

It was discovered that Mailman incorrectly handled certain URL.
An attacker could possibly use this issue to execute arbitrary code.
(CVE-2021-43331)

It was discovered that Mailman incorrectly handled certain inputs.
An attacker could possibly use this issue to expose sensitive information.
(CVE-2021-43332)

Update instructions:

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

Ubuntu 18.04 LTS:
mailman 1:2.1.26-1ubuntu0.5

Ubuntu 16.04 ESM:
mailman 1:2.1.20-1ubuntu0.6+esm2

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

References:
  https://ubuntu.com/security/notices/USN-5151-1
CVE-2021-43331, CVE-2021-43332,   https://launchpad.net/bugs/1949401,   https://launchpad.net/mailman/+bug/1949403

Package Information:
  https://launchpad.net/ubuntu/+source/mailman/1:2.1.26-1ubuntu0.5