A Mailman security update is available for Ubuntu Linux 18.04 LTS and 16.04 LTS.

USN-4348-1: Mailman vulnerabilities

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Ubuntu Security Notice USN-4348-1
April 29, 2020

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Mailman.

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 to issue execute arbitrary scripts
or HTML. (CVE-2018-0618)

It was discovered that Mailman incorrectly handled certain inputs.
An attacker could possibly use this issue to display arbitrary text
on a web page. (CVE-2018-13796)

It was discovered that Mailman incorrectly handled certain files.
An attacker could possibly use this issue to execute arbitrary code.
(CVE-2020-12137)

Update instructions:

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

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

Ubuntu 16.04 LTS:
mailman 1:2.1.20-1ubuntu0.4

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

References:
  https://usn.ubuntu.com/4348-1
CVE-2018-0618, CVE-2018-13796, CVE-2020-12137

Package Information:
  https://launchpad.net/ubuntu/+source/mailman/1:2.1.26-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/mailman/1:2.1.20-1ubuntu0.4