CVE-2021-24096 is a vulnerability that affects the Microsoft Exchange Server. It is categorized as a remote code execution vulnerability, which means that an attacker could use it to execute arbitrary code on the vulnerable system. The vulnerability was discovered in March 2021 and was assigned a Common Vulnerabilities and Exposures (CVE) identifier shortly thereafter.
The vulnerability was caused by a flaw in the Exchange Control Panel (ECP) component of the Microsoft Exchange Server. Specifically, the ECP did not properly validate user input, allowing an attacker to inject malicious code into a web request. If successful, this could allow the attacker to take control of the affected Exchange Server and potentially access sensitive information or perform other malicious actions.
Microsoft released patches for CVE-2021-24096 as part of its April 2021 security updates. However, it later emerged that a number of organizations had been successfully targeted by attackers using exploits for the vulnerability prior to the release of the patch. This led to concerns about the scale of the attack and prompted urgent warnings from cybersecurity experts for organizations to apply the patches immediately to protect against further exploitation.