SB2021030919 - Multiple vulnerabilities in Microsoft SharePoint Server

Description

This security bulletin contains information about 3 vulnerabilities.

1) Information disclosure (CVE-ID: CVE-2021-27052)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in the Microsoft SharePoint Server. A remote authenticated attacker can gain unauthorized access to sensitive information on the system.

2) Spoofing attack (CVE-ID: CVE-2021-24104)

CWE-ID: CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data. A local administrator can spoof page content.

3) Code Injection (CVE-ID: CVE-2021-27076)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the Microsoft SharePoint Server. A remote authenticated attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27052
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-24104
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27076