IT Pro is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

Microsoft Exchange servers break thanks to 'Y2K22' bug

On-premises Exchange servers are failing to deliver mail because they can't handle 2022 as a date format

Microsoft has released an emergency patch for a flaw in Microsoft Exchange that prevented emails from sending at the turn of the new year.

Businesses running on-premise Microsoft Exchange environments reported encountering issues whereby emails were stuck in a queue instead of sending after the yearly date changed to 2022.

The issue has been attributed to Exchange's malware scanning engine which manages dates in the form of 32-bit variables. The variable's maximum integer value is 2,147,483,647 but a variable of 2,201,010,001 is required to display the date as 1 January 2022 - a value that exceeds the maximum and caused the engine to crash.

Microsoft said the situation is not caused by a fault in either Exchange or its malware-scanning engine that affects the effective running of the products, but rather the engine's date-checking process. Microsoft also said this is not a cyber security issue.

Customers can check if the issue is affecting their on-premise solutions by checking the Application event log on the Exchange Server for the following errors, specifically event 5300 and 1106 (FIPFS).

Microsoft Exchange Server application log error message

Microsoft

Microsoft Exchange Server application log error message

Microsoft

Microsoft Exchange customers will need to intervene and apply the patch themselves in order to restore smooth email functionality. Microsoft detailed the step-by-step process customers can follow if they wish to patch manually, and also supplied a downloadable script for customers who want to take the automated solution. 

The script "will take some time to make the necessary changes, download the updated files, and clear the transport queues," Microsoft said. Whether customers choose the automated or manual steps towards remediation, they must be carried out on every on-premises Exchange 2016 and Exchange 2019 server. The automated script can run on multiple servers in parallel.

Members of the IT community have dubbed the issue the 'Y2K22' bug for its similarity between it and the issue that threatened to break all computers at the turn of the millennium. 

Both issues are based on the way computers handle dates and it required millions in investment and lots of work to combat the original Y2K bug.

Featured Resources

Accelerating AI modernisation with data infrastructure

Generate business value from your AI initiatives

Free Download

Recommendations for managing AI risks

Integrate your external AI tool findings into your broader security programs

Free Download

Modernise your legacy databases in the cloud

An introduction to cloud databases

Free Download

Powering through to innovation

IT agility drive digital transformation

Free Download

Recommended

Microsoft reportedly blocks Russian Windows 10 and Windows 11 downloads
Microsoft Windows

Microsoft reportedly blocks Russian Windows 10 and Windows 11 downloads

20 Jun 2022
IT Pro News in Review: UK tech raises $16bn, Microsoft acquires Miburo, largest DDoS attack mitigated
Business strategy

IT Pro News in Review: UK tech raises $16bn, Microsoft acquires Miburo, largest DDoS attack mitigated

17 Jun 2022
Proofpoint details 'dangerous' ransomware flaw in SharePoint and OneDrive
ransomware

Proofpoint details 'dangerous' ransomware flaw in SharePoint and OneDrive

17 Jun 2022
Microsoft silent patches called “a grossly irresponsible policy”
cyber security

Microsoft silent patches called “a grossly irresponsible policy”

15 Jun 2022

Most Popular

Actively exploited server backdoor remains undetected in most organisations' networks
cyber attacks

Actively exploited server backdoor remains undetected in most organisations' networks

1 Jul 2022
Macmillan Publishers hit by apparent cyber attack as systems are forced offline
Security

Macmillan Publishers hit by apparent cyber attack as systems are forced offline

30 Jun 2022
Former Uber security chief to face fraud charges over hack coverup
data breaches

Former Uber security chief to face fraud charges over hack coverup

29 Jun 2022