On March 2, 2021, Microsoft published information about four critical cybersecurity vulnerabilities in its widely used Exchange email server software that are being actively exploited. It also released cybersecurity 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.
After identifying the vulnerabilities, Microsoft issued patches to fix the problems and provided advice on how to respond if systems have already been affected.
These cybersecurity issues can be really damaging for anybody running an Exchange mail server, as attackers can run any code on the server and compromise a business’s email, allowing them to impersonate anybody in the business.
They could also read all emails stored on the server and potentially compromise more systems within the businesses’ network.
It’s important to clear up exactly who the cybersecurity vulnerabilities affected — being anybody running their own instance of Exchange, with a higher risk identified 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 on cloud providers.
However, using a cloud-hosted version of Exchange wouldn’t necessarily solve the problem, as the vulnerabilities still exist. What’s more, larger enterprises will likely still choose — or be required by regulation — to also run a local Exchange server that can be exploited in the same way.
Another open issue with moving mail servers to the cloud is that it also gives the provider access to all non-encrypted emails by default. End-to-end encryption would increase security, but is not currently standard practice.
As the vulnerabilities existed in versions of the Exchange software released as far back as 2010, it is assumed that more skilled attackers have already used them. This raises a fundamental question about the quality of the software, which Microsoft has been developing since 1996. Why did Microsoft not spot these vulnerabilities earlier?
Another question: if Microsoft knew about the vulnerabilities in early January, why did it take two months to alert its customers?
We also need to consider the bigger picture of how we deal with vulnerabilities in software that are building the backbone of our network infrastructure. There is a basic conflict between building offensive cybersecurity capabilities, and protecting our own businesses and citizens.
Imagine you are tasked with building offensive cybersecurity capabilities. You discover these vulnerabilities in Microsoft Exchange. Would you alert the vendor, Microsoft in this case, to make sure they are fixed as soon as possible, or would you keep them secret to not to lose your great new cyber weapon? Secretly having access to an organisation’s email could be very valuable for law enforcement or intelligence agencies.
Australia’s Cyber Security Strategy 2020 does not address the contradiction between establishing offensive cybersecurity capabilities and protecting Australians from cybersecurity vulnerabilities.
The establishment of offensive cybersecurity capabilities is explicitly mentioned in the strategy. In contrast, the detection of vulnerabilities with the goal of mitigation is unclear.
There is also no clear guideline regarding openness about existing vulnerabilities — which would empower Australian citizens to react to them. Australia has the expertise across the public sector, private sector and civil society to have this important dialogue on how to best protect Australian citizens and businesses.
This article was originally published on The Conversation.
