Advisory Details

June 16th, 2023

(Pwn2Own) Microsoft SharePoint GenerateProxyAssembly Code Injection Remote Code Execution Vulnerability

CVE ID	CVE-2023-24955
CVSS SCORE	8.8, AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS	Microsoft
AFFECTED PRODUCTS	SharePoint
VULNERABILITY DETAILS	This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft SharePoint. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the GenerateProxyAssembly method. The issue results from the lack of proper validation of a user-supplied string before using it to execute C# code. An attacker can leverage this vulnerability to execute code in the context of SharePoint farm service account.
ADDITIONAL DETAILS	Microsoft has issued an update to correct this vulnerability. More details can be found at: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-24954
DISCLOSURE TIMELINE	2023-03-30 - Vulnerability reported to vendor 2023-06-16 - Coordinated public release of advisory 2023-06-20 - Advisory Updated
CREDIT	Nguyễn Tiến Giang (@testanull) of STAR Labs SG Pte. Ltd.

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