SB2021121449 - Multiple vulnerabilities in Microsoft SharePoint Server

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Spoofing attack (CVE-ID: CVE-2021-43242)

The vulnerability allows a remote attacker to perform spoofing attack.

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

2) Spoofing attack (CVE-ID: CVE-2021-42320)

The vulnerability allows a remote attacker to perform spoofing attack.

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

3) Input validation error (CVE-ID: CVE-2021-42309)

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted request to Microsoft SharePoint Server and execute arbitrary code on the system.

4) Input validation error (CVE-ID: CVE-2021-42294)

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted request to Microsoft SharePoint Server and execute arbitrary code on the system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43242
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42320
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42309
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42294