Security

Microsoft Patch Tuesday for May 2021 fix 4 critical flaws

Microsoft Patch Tuesday for May 2021 security updates addressed 55 vulnerabilities, four are rated as Critical.

Microsoft Patch Tuesday for May 2021 security updates address 55 vulnerabilities in Microsoft Windows, .NET Core and Visual Studio, Internet Explorer (IE), Microsoft Office, SharePoint Server, Open-Source Software, Hyper-V, Skype for Business and Microsoft Lync, and Exchange Server.

Four vulnerabilities are rated as Critical, 50 as Important and the remaining one as Moderate severity.

Three of these bugs are publicly known but none are actively exploited in the wild at the time of release, 13 of these bugs were reported through the ZDI program.

The critical issues addressed by Microsoft are:

CVE-2021-31166 – HTTP Protocol Stack Remote Code Execution Vulnerability
The flaw could be exploited by an unauthenticated attacker by sending a specially crafted packet to a targeted server utilizing the HTTP Protocol Stack (http.sys) to process packets

CVE-2021-28476 – Hyper-V Remote Code Execution Vulnerability
The flaw could allow a guest VM to force the Hyper-V host’s kernel to read from an arbitrary, potentially invalid address.

CVE-2021-27068 – Visual Studio Remote Code Execution Vulnerability
CVE-2020-24587 – Windows Wireless Networking Information Disclosure Vulnerability
An attacker can trigger this issue to disclose the contents of encrypted wireless packets on an affected system.

The full list of CVEs released by Microsoft for May 2021 is available here.

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Pierluigi Paganini

(SecurityAffairs – hacking, Microsoft Patch Tuesday)

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Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.

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