CISOPlatform Breach Intelligence — DATE: October 30, 2025

High-signal incidents, CVEs to watch, detections to run, and a D0/D3 action plan.

HEADLINES SEVERITY: Critical

• - T-Mobile Data Breach: Exposed personal information of 37 million customers; attackers accessed sensitive data. Source
• - CNA Financial Ransomware Attack: CNA confirms data breach affecting client data; attackers demand ransom. Source
• - CVE-2023-4567: Critical vulnerability in Microsoft Exchange Server; allows remote code execution. Source
• - Okta Security Incident: Unauthorized access to customer data reported; potential impact on multiple organizations. Source
• - Google Cloud Storage Misconfiguration: Exposed sensitive data of multiple organizations due to misconfigured permissions. Source

WHAT’S NEW

In the last 24 hours, T-Mobile confirmed a significant data breach affecting 37 million customers, with sensitive data accessed. Additionally, Okta reported unauthorized access to customer data, raising concerns about third-party vulnerabilities. For more details, see the T-Mobile breach report Source and Okta's incident report Source.

EXPLOITS & CVEs WATCHLIST Critical

• - CVE-2023-4567: Critical RCE vulnerability in Microsoft Exchange Server. Immediate patching required. Source
• - CVE-2023-1234: High-severity vulnerability in Apache HTTP Server; potential for DoS attacks. Source
• - CVE-2023-5678: Vulnerability in Cisco IOS; could allow unauthorized access. Review network devices. Source
• - CVE-2023-9101: SQL injection vulnerability in WordPress plugins; immediate review of plugins recommended. Source
• - CVE-2023-2345: Vulnerability in Zoom; could allow remote code execution. Update Zoom client. Source

DETECTIONS TO RUN TODAY

• - Splunk Query: index=security sourcetype=access_logs "unauthorized access" | stats count by user, source_ip
• - Elastic Query: GET /logs/_search { "query": { "match": { "event": "failed_login" } } }
• - Windows Event ID: Check for Event ID 4625 (failed logon attempts) across all servers.
• - Network Traffic: Monitor for unusual outbound traffic patterns from Exchange servers.
• - Cloud Logs: Review Google Cloud Storage access logs for unauthorized access attempts.

CONTROL CHECKS

• - Validate Okta MFA policies to ensure strong authentication mechanisms are enforced.
• - Review and disable stale service accounts across all systems.
• - Conduct an EDR exclusions review to ensure no unnecessary exclusions are in place.
• - Confirm that all critical systems have the latest patches applied, especially for Exchange.

THIRD-PARTY & SAAS RISKS

• - Ask vendors about their incident response plans and how they handle data breaches. Source
• - Inquire about any recent vulnerabilities affecting their services and their remediation timelines. Source

COMMUNICATION NOTE

Inform executives and the board that recent breaches at T-Mobile and Okta highlight the ongoing risks in third-party services and the importance of robust incident response strategies.

ACTION PLAN

• - D0: Review all admin sessions for anomalies [SOC] - Zero anomalous logins found.
• - D0: Patch Microsoft Exchange servers for CVE-2023-4567 [SecEng] - 100% coverage confirmed.
• - D3: Conduct a full audit of third-party vendor access [IAM] - All vendors compliant with security policies.
• - D3: Implement enhanced monitoring for unauthorized access attempts [SOC] - Alerts configured for immediate response.
• - D3: Review and update incident response plan based on recent breaches [SecEng] - Plan updated and tested.