mailman vulnerability

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

* Ubuntu 18.04 LTS
* Ubuntu 16.04 LTS

Summary

Mailman could be made to inject arbitrary content in the login
page if it received a specially crafted input.

Software Description

* mailman - Web-based mailing list manager (legacy branch)

Details

It was discovered that Mailman incorrectly handled certain inputs.
An attacker could possibly use this issue to inject arbitrary
content in the login page.

Update instructions

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

Ubuntu 18.04 LTS
mailman - 1:2.1.26-1ubuntu0.3

Ubuntu 16.04 LTS
mailman - 1:2.1.20-1ubuntu0.6

To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.

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

References

* CVE-2020-15011

--- Mystic BBS v1.12 A45 (Linux/64)
* Origin: BZ&BZ BBS (21:4/110)