CISA orders feds to patch BlueHammer flaw exploited as zero-day

A critical privilege escalation flaw in Microsoft Defender, known as BlueHammer, has been exploited in zero-day attacks, prompting the Cybersecurity and Infrastructure Security Agency (CISA) to mandate its immediate patching across all U.S. federal agencies. The vulnerability allows attackers to gain elevated privileges, posing a significant threat to system security. CISA's directive underscores the urgency of addressing this flaw, given its active exploitation in the wild. Federal agencies are required to apply the necessary patches to prevent potential breaches. The fact that zero-day attacks are already targeting this vulnerability¹ highlights the rapidly diminishing window for effective patching. So what matters to security practitioners is that they must swiftly assess their exposure to this flaw and apply patches to prevent attackers from leveraging BlueHammer to escalate privileges and gain unauthorized access to sensitive systems.