2021 in computing

outage of Facebook, Instagram, WhatsApp, and Oculus in October 2021

Log4Shell (CVE-2021-44228) is a vulnerability reported in November 2021 in Log4j, a popular Java logging framework, involving arbitrary code execution and exploited as a zero-day vulnerability. The vulnerability had existed unnoticed since 2013 and was privately disclosed to the Apache Software Foundation, of which Log4j is a project, by Chen Zhaojun of Alibaba Cloud's security team on 24 November 2021.

2020–21 economic shortage caused by demand for semiconductor chips exceeding supply

series of cyberattacks exploiting Microsoft's email and calendar server software