Widespread Zero‑Day Exploit Targets Microsoft SharePoint in 2025

In mid‑2025, a widespread zero‑day exploit targeting Microsoft SharePoint shook enterprises and government organisations across India. This critical vulnerability allowed attackers to bypass security, steal sensitive documents, and even deploy ransomware. In this article, we’ll explore:

• What the zero‑day exploit entails

• Its impact on Indian businesses

• Preventive and response strategies

• Key insights to strengthen SharePoint security

What Is a Zero‑Day Exploit on Microsoft SharePoint?

A zero‑day exploit is a software vulnerability that hackers discover and exploit before the developer learns of it or issues a patch. Unlike common malware that relies on known malware signatures, zero‑day exploits rely on unknown flaws. In early July 2025, Microsoft confirmed a zero‑day flaw in SharePoint allowing attackers to gain admin privileges remotely.

How SharePoint Was Compromised

• Attack vector: Manipulating unsecured upload and preview functions

• Exploit Goal: Execute malicious code with administrative access

• Techniques Used: SQL injection + remote code execution (RCE)

Why SharePoint Targets Matter

• Widely used by Indian public services, government portals, education systems, and enterprises

• Central repository for sensitive documents—including HR, financial, legal files

Real‑World Example: Indian PSU Hit by SharePoint Zero‑Day

In mid‑2025, a publicly listed PSU in India reported a security breach traced back to compromised SharePoint servers. Attackers exploited the zero‑day to deploy ransomware, encrypting crucial reports on budgets and payroll.

Consequences included:

• ₹5 crore estimated financial loss

• Two days of operational downtime

• Customer complaints and reputational damage

Zero‑Day Exploit Targets Microsoft SharePoint: Impact & Statistics

• Nearly 2 in 5 Indian organisations using on‑premises SharePoint lacked formal incident response plans.

• 80% of global SharePoint sites applied the July patch within two weeks, but 20% of Indian servers remained exposed by end‑July 2025.

Immediate Mitigation: What Every Indian Business Should Do Now

1. Apply Microsoft Patches Immediately
   Microsoft released a critical security update on July 15, 2025, with follow-up hotfixes July–August 2025. Ensure both SharePoint and Windows Server are fully patched.

2. Enable Enhanced Monitoring & Logging
   Use SIEM tools to monitor logs like file uploads, admin access, and remote code execution. Set alerts for unusual admin activity.

3. Segment and Harden Networks
   Restrict external access to SharePoint Admin Center and file servers. Place SharePoint on segmented, monitored networks with IDS/IPS.

4. Apply Principle of Least Privilege (PoLP)
   Review and audit all privileged accounts. Ensure regular access reviews and immediate removal of inactive accounts.

5. Backup & Recovery
   Maintain off‑site or secure cloud backups. Test restore processes regularly under ransomware attack drills.

Long‑Term Best Practices to Prevent Future Exploits

• SharePoint Security Audits
  Annual third-party audits for code and infrastructure vulnerabilities.

• User Training & Awareness
  Educate employees on the risk of phishing and evolving zero‑day threats.

• Virtual Patching
  Deploy WAF rules to block malicious actions while awaiting official patches.

• Multi‑Factor Authentication (MFA)
  Enforce MFA for all SharePoint access, especially administration.

• Incident Response Readiness
  Align with CERT-In and NCIIPC incident reporting standards. Mock drills minimize loss during real breaches.

The Indian Cyber Landscape: SharePoint Under Threat

India ranks among the top 5 nations globally for cyber incidents in 2025. In Q2, CERT-In logged a 35% increase in exploitation of software vulnerabilities. Many breaches occurred in mid-layer services like SharePoint, often without publicly disclosed root causes due to brand concerns.

Government Guidelines

• CERT-In’s Advisory No. 21/2025 focuses on zero‑day vulnerabilities in enterprise software including SharePoint.

• The Indian Computer Security Emergency Response Team urges immediate patch management and mandatory vulnerability disclosure for critical infrastructure.

Case Study: Bank’s Proactive Response

XYZ National Bank, headquartered in Mumbai, faced repeated phishing and probing targeting its SharePoint instance. In April 2025 it:

• Enabled MFA across all access layers

• Applied a third-party WAF

• Instituted 24×7 SOC‑based monitoring

• Ran monthly penetration tests including exploit simulations

🛡️ Result: When the zero‑day was identified in July, Microsoft patches were applied within 8 hours, and monitoring rules hot‑patched immediately. No breach occurred, and only 50 MB of log data needed manual review.

How Small & Mid‑Size Firms Can Stay Ahead

Optimal Affordable Measures

• Cloud‑based SharePoint (Microsoft 365) – fully patched by Microsoft

• Cloud WAF features by Azure/GCP/AWS

• Managed detection & response (MDR) providers for resource-strapped teams

Cost Comparison Table

Action Plan: Step‑by‑Step Checklist

1. Audit: List all SharePoint servers and check patch status.

2. Patch: Immediately apply July 15 + follow-up hotfixes.

3. Log: Set up or enhance logging of admin actions and uploads.

4. Segment: Restrict network and implement firewall rules.

5. MFA: Enforce multi-factor authentication.

6. Test: Perform penetration testing and SOC alerts.

7. Backup: Secure regular, tested recovery backups.

8. Train: Conduct staff awareness sessions.

9. Report: Register incidents with CERT‑In/NCIIPC per guidelines.

Why “Zero‑Day Exploit Targets Microsoft SharePoint” Matters to India

• SharePoint’s extensive use in sectors—government, autoimmune, private corporations

• In 2025, nearly 60% of Indian public bodies use SharePoint for internal document sharing

• Unpatched zero‑days can affect national security, public finances, and citizens’ privacy

Optimizing Your SharePoint Security Modernization

• Hybrid Infrastructure? Secure both on‑prem and cloud setups

• Migrate? Consider moving to Microsoft 365 for automated protections

• Third‑party support? Employ MSSPs or MDR vendors for enhanced protection

Conclusion

The 2025 zero‑day exploit targeting Microsoft SharePoint is a wake‑up call for Indian enterprises and public agencies. The threat is real—delays in patching, lack of monitoring, and inadequate response policies can turn this vulnerability into a full‑scale breach.

Key Takeaways

• Implement immediate patching

• Strengthen monitoring and access controls

• Enforce MFA and principle of least privilege

• Regularly test and back up systems

Act now to safeguard your organisation’s SharePoint infrastructure—and by extension, your data, reputation, and user trust. This is not just a technical issue; it’s vital to national and organisational resilience.

📣 Call to Action

Start safeguarding today:

1. Download our free SharePoint Security Checklist

2. Register for our upcoming live webinar (aug 2025) on zero‑day prevention strategies

3. Join a community of security professionals building a stronger, safer SharePoint ecosystem in India

Secure your SharePoint. Secure your future.