Urgent Unfixed SharePoint Zero-Day Vulnerability Under Active Attack, Compromises Over 75 Company Servers

Urgent Unfixed SharePoint Zero-Day Vulnerability Under Active Attack, Compromises Over 75 Company Servers

Critical Vulnerability in Microsoft SharePoint Server: What You Need to Know

A critical security vulnerability identified in Microsoft SharePoint Server, CVE-2025-53770, is currently being exploited in a widespread attack that allows unauthorized code execution. With a CVSS score of 9.8, it exposes on-premises SharePoint systems to severe risks.

Key Details

  • Who: Microsoft and Viettel Cyber Security
  • What: A zero-day vulnerability enabling remote code execution.
  • When: Discovered and publicly announced on July 19, 2025.
  • Where: Affects on-premises SharePoint Server; SharePoint Online is unaffected.
  • Why: Attackers leverage deserialization of untrusted data to execute commands before authentication.
  • How: By exploiting this flaw, attackers can gain unauthorized access and move laterally within the network, often camouflaging their activities.

Why It Matters

This vulnerability has severe implications for:

  • Enterprise Security: It allows attackers to bypass standard authentication, potentially compromising sensitive data across multiple organizations, including government entities.
  • Hybrid Cloud Adoption: Companies using a mixed environment could face challenges securing on-premises resources, affecting their cloud strategy.
  • Compliance and Risk Management: Organizations must act swiftly to mitigate risks or face potential compliance violations.

Takeaway for IT Teams

IT professionals should immediately enable Antimalware Scan Interface (AMSI) integration in their SharePoint environments and deploy Defender AV to minimize exposure until a patch is released. It’s also advisable to disconnect impacted servers from the internet if AMSI cannot be enabled. Continuous monitoring and rapid incident response are crucial during this ongoing threat landscape.

For more curated news and infrastructure insights, visit TrendInfra.com.

Meena Kande

meenakande

Hey there! I’m a proud mom to a wonderful son, a coffee enthusiast ☕, and a cheerful techie who loves turning complex ideas into practical solutions. With 14 years in IT infrastructure, I specialize in VMware, Veeam, Cohesity, NetApp, VAST Data, Dell EMC, Linux, and Windows. I’m also passionate about automation using Ansible, Bash, and PowerShell. At Trendinfra, I write about the infrastructure behind AI — exploring what it really takes to support modern AI use cases. I believe in keeping things simple, useful, and just a little fun along the way

Leave a Reply

Your email address will not be published. Required fields are marked *