Kalper (Slashdot reader #57,281) shares news from Bleeping Computer:
Microsoft Exchange on-premise servers cannot deliver email starting on January 1st, 2022, due to a “Year 2022” bug in the FIP-FS anti-malware scanning engine.
Starting with Exchange Server 2013, Microsoft enabled the FIP-FS anti-spam and anti-malware scanning engine by default to protect users from malicious email. According to numerous reports from Microsoft Exchange admins worldwide, a bug in the FIP-FS engine is blocking email delivery with on-premise servers starting at midnight on January 1st, 2022.
Security researcher and Exchange admin Joseph Roosen said that this is caused by Microsoft using a signed int32 variable to store the value of a date, which has a maximum value of 2,147,483,647. However, dates in 2022 have a minimum value of 2,201,010,001 or larger, which is greater than the maximum value that can be stored in the signed int32 variable, causing the scanning engine to fail