Microsoft patches Exchange Server zero-day exploited in attacks

Microsoft has issued a patch for a zero-day vulnerability in Exchange Server, which was being exploited by threat actors to execute arbitrary JavaScript code through cross-site scripting attacks targeting Outlook Web Access users. The vulnerability allows attackers to inject malicious code, potentially leading to unauthorized access and data breaches. This exploit highlights the critical need for swift patch deployment, as the window for protection is rapidly diminishing. The fact that this vulnerability was actively being exploited¹ underscores the urgency of assessing exposure and applying the patch immediately. Microsoft's prompt response to the vulnerability is crucial in mitigating potential damage. The patch is essential for organizations relying on Exchange Server to prevent XSS attacks and protect sensitive user data. So what matters most to practitioners is that they must assess their exposure to this vulnerability and apply the patch without delay to prevent falling victim to these attacks.