PoC exploit code for ProxyNotShell Microsoft Exchange bugs released online

Proof-of-concept exploit code for two actively exploited Microsoft Exchange ProxyNotShell flaws released online.

Proof-of-concept exploit code has been released online for two actively exploited vulnerabilities in Microsoft Exchange, known as ProxyNotShell.

The two flaws are:

CVE-2022-41040 – Microsoft Exchange Server Elevation of Privilege Vulnerability
CVE-2022-41082 – Microsoft Exchange Server Remote Code Execution Vulnerability

they impact Exchange Server 2013, 2016, and 2019, an authenticated attacker can trigger them to elevate privileges to run PowerShell in the context of the system and gain arbitrary or remote code execution on vulnerable servers.

Cybersecurity firm GreyNoise confirmed that threat actors are attempting to exploit the flaws since late September, Bleeping Computer reported.

Microsoft addressed both vulnerabilities with the release of Patch Tuesday updates for November 2022 security updates.

This week the popular researcher Will Dormann confirmed that PoC exploit code released by the security researcher Janggggg, which was exploited by threat actors in the wild, works against Exchange Server 2016 and 2019, and even against 2013 with some modifications. The expert demonstrated how to exploit the bug to execute calc.exe as SYSTEM.

Microsoft urges its customers to install the updates immediately to be protected against attacks exploring these flaws. The IT giant confirmed that they are aware of active exploits of related vulnerabilities that have been used in limited targeted attacks.

“Because we are aware of active exploits of related vulnerabilities (limited targeted attacks), our recommendation is to install these updates immediately to be protected against these attacks.” states Microsoft.

“Mitigations are not actual code fixes of specific vulnerabilities. Please install the November 2022 (or later) SU on your Exchange servers to address CVE-2022-41040 and CVE-2022-41082.”

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Pierluigi Paganini

(SecurityAffairs – hacking, ProxyNotShell)

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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”.