On March 2, 2021, Microsoft published information about four critical vulnerabilities in its widely used Exchange email server software that are being actively exploited. It also released security updates for all versions of Exchange back to 2010.
Microsoft has told cybersecurity expert Brian Krebs it was notified of the vulnerabilities in “early January”. The Australian Cyber Security Centre has also issued a notice on the vulnerabilities.
The situation has been widely reported in the general media as well as specialist cybersecurity sites, but often inaccurately. But the situation also highlights a contradiction in government cybersecurity policy.
When governments find flaws in widely used software, they may not publish the details in order to build up their own offensive cybersecurity capabilities, i.e. the ability to target computers and networks for spying, manipulation and disruption. Operations like this often rely on exploiting vulnerabilities in commercial software — thus leaving their own citizens vulnerable to attack as a consequence.
Microsoft has issued patches to fix the vulnerabilities and provided advice on how to respond if systems have already been affected.
These vulnerabilities can be really damaging for anybody running their own Exchange mail server. Attackers can run any code on the server and fully compromise a business’s email, allowing them to impersonate anybody in the business. They could also read all email stored on the server and potentially compromise more systems within the businesses’ network.
Who was affected?
It’s important to clear up exactly who the vulnerabilities affected: anybody running their own instance of Exchange, and the risk was higher if web access was turned on.
An ABC/Reuters report said:
All of those affected appear to run Web versions of email client Outlook and host them on their own machines, instead of relying…