The problem can be corrected by upgrading the affected package to version 2.0.50-12ubuntu4.1. In general, a standard system upgrade is sufficient to effect the necessary changes.
Chintan Trivedi discovered a Denial of Service vulnerability in apache2. The field length limit was not enforced for certain malicious requests. This could allow a remote attacker who is able to send large amounts of data to a server to cause HTTP server instances to consume proportional amounts of memory, which can render the service unavailable.