Microsoft Releases October 2023 Patches for 103 Flaws, Including 2 Active Exploits

Microsoft has released its Patch Tuesday updates for October 2023, addressing a total of 103 flaws in its software, two of which have come under active exploitation in the wild.

Of the 103 flaws, 13 are rated Critical and 90 are rated Important in severity. This is apart from 18 security vulnerabilities addressed in its Chromium-based Edge browser since the second Tuesday of September.

The two vulnerabilities that have been weaponized as zero-days are as follows -

• CVE-2023-36563 (CVSS score: 6.5) - An information disclosure vulnerability in Microsoft WordPad that could result in the leak of NTLM hashes
• CVE-2023-41763 (CVSS score: 5.3) - A privilege escalation vulnerability in Skype for Business that could lead to exposure of sensitive information such as IP addresses or port numbers (or both), enabling threat actors to gain access to internal networks

“To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system,” Microsoft said in an advisory for CVE-2023-36563.

“Additionally, an attacker could convince a local user to open a malicious file. The attacker would have to convince the user to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file.”

Also fixed by Redmond are dozens of flaws impacting Microsoft Message Queuing (MSMQ) and Layer 2 Tunneling Protocol that could lead to remote code execution and denial-of-service (DoS).

The security update further resolves a severe privilege escalation bug in Windows IIS Server (CVE-2023-36434, CVSS score: 9.8) that could permit an attacker to impersonate and login as another user via a brute-force attack.

The tech giant has also released an update for CVE-2023-44487, also referred to as the HTTP/2 Rapid Reset attack, which has been exploited by unknown actors as a zero-day to stage hyper-volumetric distributed denial-of-service (DDoS) attacks.

“While this DDoS has the potential to impact service availability, it alone does not lead to the compromise of customer data, and at this time we have seen no evidence of customer data being compromised,” it said.

Finally, Microsoft has announced that Visual Basic Script (aka VBScript), which is often exploited for malware distribution, is being deprecated, adding, “in future releases of Windows, VBScript will be available as a feature on demand before its removal from the operating system.”

Software Patches from Other Vendors

In addition to Microsoft, security updates have also been released by other vendors since the start of the month to rectify several vulnerabilities, including —

• Adobe
• AMD
• Android
• Apache Projects
• Apple
• Aruba Networks
• Arm
• Atlassian
• Atos
• Cisco
• Citrix
• CODESYS
• Dell
• Drupal
• F5
• Fortinet
• GitLab
• Google Chrome
• Hitachi Energy
• HP
• IBM
• Juniper Networks
• Lenovo
• Linux distributions Debian, Oracle Linux, Red Hat, SUSE, and Ubuntu
• MediaTek
• Mitsubishi Electric
• Mozilla Firefox, Firefox ESR, and Thunderbird
• Qualcomm
• Samba
• Samsung
• SAP
• Schneider Electric
• Siemens
• Sophos, and
• VMware

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