Pierluigi Paganini November 03, 2023

Researchers disclosed four zero-day flaws in Microsoft Exchange that can be remotely exploited to execute arbitrary code or disclose sensitive information on vulnerable installs.

Trend Micro’s Zero Day Initiative (ZDI) disclosed four zero-day vulnerabilities in Microsoft Exchange that can be remotely exploited by an authenticated attacker to execute arbitrary code or disclose sensitive information on vulnerable installs.

Trend Micro’s Zero Day Initiative (ZDI) reported the flaws to Microsoft on September 7th and 8th, 2023, but the IT giant has yet to fix them, despite acknowledging the vulnerabilities. ZDI opted to publicly disclose the vulnerability in compliance with its responsible disclosure policy.

Below is the list of flaws disclosed by ZDI:

• ZDI-23-1578 – Microsoft Exchange ChainedSerializationBinder Deserialization of Untrusted Data Remote Code Execution Vulnerability – This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Exchange. Authentication is required to exploit this vulnerability. The specific flaw exists within the ChainedSerializationBinder class. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of SYSTEM.
• ZDI-23-1579 – Microsoft Exchange DownloadDataFromUri Server-Side Request Forgery Information Disclosure Vulnerability – This vulnerability allows remote attackers to disclose sensitive information on affected installations of Microsoft Exchange. Authentication is required to exploit this vulnerability. The specific flaw exists within the DownloadDataFromUri method. The issue results from the lack of proper validation of a URI prior to accessing resources. An attacker can leverage this vulnerability to disclose information in the context of the Exchange server.
• ZDI-23-1580 – Microsoft Exchange DownloadDataFromOfficeMarketPlace Server-Side Request Forgery Information Disclosure Vulnerability – This vulnerability allows remote attackers to disclose sensitive information on affected installations of Microsoft Exchange. Authentication is required to exploit this vulnerability. The specific flaw exists within the DownloadDataFromOfficeMarketPlace method. The issue results from the lack of proper validation of a URI prior to accessing resources. An attacker can leverage this vulnerability to disclose information in the context of the Exchange server.
• ZDI-23-1581 – Microsoft Exchange CreateAttachmentFromUri Server-Side Request Forgery Information Disclosure Vulnerability – This vulnerability allows remote attackers to disclose sensitive information on affected installations of Exchange. Authentication is required to exploit this vulnerability. The specific flaw exists within the CreateAttachmentFromUri method. The issue results from the lack of proper validation of a URI prior to accessing resources. An attacker can leverage this vulnerability to disclose information in the context of the Exchange server.

The vulnerabilities have been discovered by Piotr Bazydlo (@chudyPB) of Trend Micro Zero Day Initiative

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Pierluigi Paganini

(SecurityAffairs – hacking, RCE)