CVE-2025-64663
📋 TL;DR
This CVE describes an elevation of privilege vulnerability in Microsoft's Custom Question Answering service. Attackers can exploit this to gain unauthorized administrative access to affected systems. Organizations using Microsoft's Custom Question Answering service are potentially affected.
💻 Affected Systems
- Microsoft Custom Question Answering
📦 What is this software?
Azure Language by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code, access sensitive data, and maintain persistent access to the environment.
Likely Case
Unauthorized administrative access to the Custom Question Answering service, potentially leading to data exfiltration or service disruption.
If Mitigated
Limited impact with proper network segmentation, least privilege access controls, and monitoring in place.
🎯 Exploit Status
CWE-918 (Server-Side Request Forgery) suggests potential for chained attacks; exploitation likely requires some initial access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-64663
Restart Required: Yes
Instructions:
1. Review Microsoft Security Update Guide for CVE-2025-64663. 2. Apply the latest security updates for Custom Question Answering. 3. Restart affected services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to Custom Question Answering services to only trusted sources.
Access Control Hardening
allImplement strict least privilege access controls and monitor for unusual administrative activity.
🧯 If You Can't Patch
- Isolate affected systems from critical networks and internet access
- Implement enhanced monitoring and alerting for suspicious administrative activities
🔍 How to Verify
Check if Vulnerable:
Check your Custom Question Answering service version against Microsoft's patched versions in their advisory.Check Version:
Check through Azure portal or deployment configuration for Custom Question Answering versionVerify Fix Applied:
Verify the service version matches or exceeds the patched version specified by Microsoft.📡 Detection & Monitoring
Log Indicators:
- Unusual administrative access patterns
- Unexpected privilege escalation events
- SSRF-related request patterns
Network Indicators:
- Anomalous outbound requests from Custom Question Answering service
- Unexpected internal service communication
SIEM Query:
source="CustomQuestionAnswering" AND (event_type="privilege_escalation" OR action="admin_access")