Microsoft’s October 2023 Patch Tuesday Addresses 3 Zero-Days, 104 Vulnerabilities

Microsoft has released its latest round of security updates for October 2023. In its most recent Patch Tuesday, the updates are intended to provide fixes for a total of 104 vulnerabilities, with a particular focus on addressing three actively exploited zero-day vulnerabilities. This threat brief delves into the situation, Microsoft’s response and recommended actions for organizations. 

What’s the update from Microsoft?  

The October 2023 Patch Tuesday updates from Microsoft tackle a wide array of vulnerabilities. In total, 104 vulnerabilities are addressed, with a striking emphasis on 45 remote code execution (RCE) vulnerabilities. Among these, 12 are rated as “Critical” by Microsoft, underscoring the significance of these vulnerabilities. 

However, the most pressing concerns revolve around the three zero-day vulnerabilities that threat actors are actively exploiting. These zero-days are as follows: 

1. CVE-2023-41763 – Skype for Business Elevation of Privilege Vulnerability: This vulnerability enables threat actors to escalate privileges within Skype for Business, potentially leading to unauthorized access or system compromise. 
2. CVE-2023-36563 – Microsoft WordPad Information Disclosure Vulnerability: Exploiting this vulnerability allows for the unauthorized retrieval of sensitive information from Microsoft WordPad, which could be used for malicious purposes. 
3. CVE-2023-44487 – HTTP/2 Protocol Denial of Service Vulnerability: This particular vulnerability lies in the HTTP/2 protocol and can be exploited for a denial of service (DoS) attack by consuming server resources. It has been observed “in the wild” between August and October 2023, making it a significant concern. 

These actively exploited zero-days demand immediate attention and action, as they pose a substantial risk to organizations relying on affected Microsoft products. The complete list of resolved vulnerabilities in the October 2023 Patch Tuesday updates can be found in the full report. 

What is Nuspire doing? 

Nuspire maintains a stringent approach to cybersecurity and promptly applies patches as they are released, adhering to vendor recommendations. Additionally, Nuspire’s security experts actively engage in threat hunting to identify any potential indications of compromise within client environments.  

How should I protect myself from these vulnerabilities? 

In light of the October 2023 Patch Tuesday updates, organizations are urged to take several critical actions: 

1. Review and Apply Security Updates: Organizations should thoroughly review Microsoft’s October 2023 security updates and apply patches to affected systems as swiftly as possible. Patch management is an essential practice to safeguard against known vulnerabilities. 

1. Prioritize Actively Exploited Vulnerabilities: Given the presence of actively exploited zero-days, it is imperative to prioritize patching these specific vulnerabilities. These patches should be applied without delay to mitigate the associated risks. 

1. Workarounds and Mitigations: In cases where immediate patching is not feasible, we advise reviewing individual CVEs from Microsoft. These may provide valuable workarounds or mitigations that can be employed to reduce exposure to the vulnerabilities. 

The cybersecurity landscape continues to evolve, and proactive measures are essential to safeguard organizations against emerging threats. Microsoft’s October 2023 Patch Tuesday updates represent a crucial step in this ongoing battle, and organizations must respond promptly to mitigate the associated risks and bolster their security posture.