On October 11th, Canonical published in a security notice details about MoinMoin vulnerabilities for its Ubuntu 12.04 LTS, Ubuntu 11.10, Ubuntu 11.04, and Ubuntu 10.04 LTS operating systems.
According to Canonical, Several security issues were fixed in MoinMoin. It was discovered that MoinMoin did not properly sanitize certain input and it incorrectly handled group names that contained virtual group names such as "All", "Known" or "Trusted".
A remote attacker could have exploited this to modify the contents or steal confidential data, within the same domain.
The security flaws can be fixed if you upgrade your system(s) to the latest python-moinmoin, specific to each operating system. To apply the update, run the Update Manager application.
In general, a standard system update will make all the necessary changes. A system restart won't be necessary to implement the changes.