Blumira Briefings

Staying on top of security news shouldn't be another full-time job.

Enter Blumira Briefings, our weekly panel series where security experts break down the headlines you might have missed, and explain what they actually mean for your security practice! 🔒

Each week, join a lineup of different Blumira experts (and sometimes special guests!) who will:

Share the top threats, suspects, and risks we're seeing across our detection and response platform
Discuss significant security stories and what they mean for YOU
Provide practical advice you can actually implement right away

••Keep it conversational, informative, and under 30 minutes

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Blumira Briefings

🦔 Blumira Briefings Ep. 15: On-Prem Exchange Risks, S3 Bucket Leaks & Direct Send Phishing Tactics

August 14, 2025 • Blumira • Season 1 • Episode 15

Welcome back to Blumira Briefings, freshly back after our summer break! Join Zoe and our panel of security experts Jake Ouellette, Michael Kellar, and Chris Furner as we dive into the week's most critical security headlines with actionable context.

What We Cover This Week:

🔐 Critical Microsoft Exchange vulnerability (CVE-2025-53786) affecting on-premises servers - 29,000+ servers remain unpatched, let’s talk why

📱 Android's August security patch addressing critical vulnerabilities, including a zero-click RCE exploit and Qualcomm Adreno GPU flaws

⏰ Windows 11 23H2 Home and Pro reaching end of support in November - why support cycles are getting shorter

☁️ Millions of records exposed through an unsecured AWS S3 bucket - how this common misconfiguration continues to cause major data breaches

📧 How attackers are abusing Microsoft 365's "Direct Send" feature to bypass security measures and appear as trusted internal senders

💡 Quick tip of the week: Run regular scans for exposed S3 buckets using tools like S3Scanner or S3Enum. Even if you don't think your organization has AWS instances, shadow infrastructure might exist without your knowledge.

Plus, Expert Insights On:

Why some organizations still maintain on-premises Exchange servers despite cloud alternatives
How to handle Android device security when updates depend on manufacturer timelines
The challenge of keeping pace with accelerating Windows update cycles
Essential cloud storage security practices to prevent data exposure
Strategies to protect against sophisticated internal email spoofing

📰 SOURCES:

Microsoft Exchange Vulnerability: https://hackread.com/29k-microsoft-exchange-servers-unpatched-networks-risk/

Android Security Update: https://www.malwarebytes.com/blog/news/2025/08/android-critical-vulnerabilities-patched-update-as-soon-as-you-can

Windows 11 End of Support: https://www.bleepingcomputer.com/news/microsoft/windows-11-23h2-home-and-pro-reach-end-of-support-in-november/ AWS S3 Bucket Exposure: https://hackread.com/hacker-accesses-imdatacenter-records-exposed-aws-bucket/

Microsoft 365 Direct Send Phishing: https://www.darkreading.com/cyber-risk/phishers-abuse-m365-direct-send-to-spoof-internal-users

🔗 LINKS:

Atomic Red Team Testing Framework: https://www.atomicredteam.io/

S3Scanner GitHub Repository: https://github.com/sa7mon/S3Scanner

S3Enum GitHub Repository: https://github.com/koenrh/s3enum

DorkSearch Tool: https://dorksearch.com/

Google Dorks Awesome List : https://github.com/Tobee1406/Awesome-Google-Dorks