A new wave of cyber threats has prompted organizations worldwide to evaluate their digital defenses, as Microsoft announced the release of critical security updates affecting a wide range of its products. The patches target numerous weaknesses, one of which is an actively exploited zero-day vulnerability in WebDAV that had already been leveraged in a targeted cyberattack. Analysts highlight that as businesses adopt digital collaboration tools for productivity, understanding the implications of such security flaws becomes increasingly important for ensuring safe enterprise operations. There have been growing concerns surrounding WebDAV’s security over the years, but few incidents have drawn as much attention to its vulnerabilities as the details emerging from this latest patch cycle.
Earlier reports on Microsoft’s monthly patches have typically focused on the breadth of vulnerabilities, but seldom have they drawn attention to the specific exploitation of WebDAV by sophisticated threat actors. Compared to earlier announcements, this patch cycle has drawn sharper scrutiny due to the disclosure that Stealth Falcon, a group with a history of focused espionage campaigns, utilized the zero-day flaw for targeted attacks. Furthermore, while prior updates included similar volumes of vulnerabilities, this instance has attracted more significant industry commentary due to the risk factors associated with enterprise use of WebDAV and the extent of its deployment in business environments.
How Did Stealth Falcon Exploit CVE-2025-33053?
Stealth Falcon, a cyber-espionage group, exploited the WebDAV vulnerability registered as CVE-2025-33053, enabling remote code execution on select targets. Check Point Research found that a Turkish defense company’s systems were infiltrated in March using this security gap. Their findings suggest that Stealth Falcon’s operations primarily target government and defense entities throughout the Middle East and North Africa, and their techniques involve a blend of infection tactics, including leveraging legitimate tools and multiple payload delivery stages.
What Makes WebDAV a Preferred Target?
WebDAV, integrated into Microsoft’s ecosystem for remote file management, frequently appears in enterprise systems and is often insufficiently secured. Security professionals note that business imperatives drive organizations to enable WebDAV, sometimes inadvertently heightening their exposure to cyber risks. Mike Walters, co-founder of Action1, estimated.
“Many organizations enable WebDAV for legitimate business needs — often without fully understanding the security risks it introduces.”
This, coupled with widespread adoption, led experts to warn that the number of potentially affected organizations could reach into the millions.
Are There Other Significant Vulnerabilities Addressed?
Microsoft’s update spans a total of 66 vulnerabilities, encompassing one that is classified as critical—CVE-2025-47966. This flaw in Microsoft Power Automate may permit unauthorized access to sensitive information and privilege escalation. In addition to these, the patches account for 43 high-severity and 22 medium-severity flaws, with 17 of those vulnerabilities affecting Microsoft Office and its standalone products. Of these Office-related issues, three are considered more likely to be exploited based on Microsoft’s own assessments.
Microsoft’s release of this comprehensive security update has drawn significant interest from cybersecurity experts and organizations alike, particularly due to its focus on an active zero-day exploited by an established threat actor. The decision by the Cybersecurity and Infrastructure Security Agency to list the WebDAV vulnerability in its known catalog underscores its perceived threat level. As WebDAV continues to be integral for enterprise workflows, persistent concerns over its security posture remain a pressing issue for system administrators. For businesses relying on Microsoft products, promptly deploying these updates is essential for reducing exposure, especially as attackers adapt their methods to exploit unpatched environments. Users can review the detailed list of patched vulnerabilities through Microsoft’s Security Response Center, ensuring they remain proactively informed and protected.
- Microsoft released security fixes for 66 vulnerabilities across multiple products.
- Stealth Falcon exploited a zero-day in WebDAV for targeted cyber-espionage.
- WebDAV’s extensive use increases cyber risk for millions of organizations worldwide.
