CVE-2023-29357
Microsoft SharePoint Server Elevation of Privilege Vulnerability
DESCRIPTION
CVE-2023-29357 is a security vulnerability affecting Microsoft SharePoint Server, a popular collaboration and document management platform. This vulnerability is classified as an "Elevation of Privilege" (EoP), meaning that if successfully exploited, an attacker can gain higher-level access than they are authorized to have within the SharePoint environment.
In summary, CVE-2023-29357 is a critical security vulnerability in Microsoft SharePoint Server 2019 that allows an unauthenticated attacker to impersonate a SharePoint user, leading to elevated privileges and unauthorized actions within the SharePoint environment. To mitigate this risk, organizations are strongly advised to apply provided security updates and consider additional security measures such as integrating AMSI and Microsoft Defender.
This vulnerability is rated high with a score of 9.8 based on the Common Vulnerability Scoring System (CVSS) version 3. This classification describes the vulnerability as "critical," indicating that it has serious potential for exploitation.
AFFECTED SYSTEMS
CVE-2023-29357 affects systems running Microsoft SharePoint Server, particularly the SharePoint Server 2019 version. Systems running this software version may be vulnerable to this vulnerability if they have not been updated with the security patches provided by Microsoft. The systems affected by this vulnerability are:
Microsoft SharePoint Server 2019: This vulnerability specifically impacts installations of SharePoint Server 2019. Systems running this software version may be targeted by attackers attempting to exploit this vulnerability.
VULNERABILITY IMPACT
CVE-2023-29357 has the potential for serious impact on the affected environment, especially if exploited by malicious attackers. The main impacts of this vulnerability are as follows:
• Access to Privileged Rights: If attackers successfully impersonate a user with privileged rights, such as an administrator, they can gain control over SharePoint configurations and even broader network infrastructure. This could lead to significant system manipulation and potentially unrestricted access.
• Potential for Malicious Actions: In addition to unauthorized access, attackers exploiting CVE-2023-29357 can also perform other malicious actions within the SharePoint environment. This could include data deletion, configuration changes, spreading malware, or even attempting to exploit other vulnerabilities within the system.
• Potential Unauthorized Access to Sensitive Data: If an attacker successfully exploits this vulnerability, they can impersonate a valid SharePoint user. This means the attacker can gain unauthorized access to sensitive data stored within the SharePoint environment. This data may include business documents, personal information, or other critical data.
RECOMMENDATIONS
The primary recommendations for CVE-2023-29357 are as follows:
1. Security Updates: The most important step is to install the security updates or patches provided by Microsoft. These updates will fix the vulnerability and secure SharePoint Server 2019 systems from CVE-2023-29357. Organizations should promptly update their software to the patched version, which is build 16.0.10399.20005 or higher.
2. Implementation of Additional Protection Measures: In addition to updates, Microsoft also recommends implementing several additional protection measures, especially for organizations unable to immediately install updates. One of the mentioned steps is the integration of AMSI (Antimalware Scan Interface) and the use of Microsoft Defender on SharePoint Server farms. This can add an extra layer of protection against this vulnerability. Guidance for configuring AMSI with SharePoint Server can be found in Microsoft's official documentation.