SB2021071338 - Multiple vulnerabilities in Microsoft SharePoint Server
Published: July 13, 2021 Updated: July 19, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Spoofing attack (CVE-ID: CVE-2021-34517)
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to incorrect processing of user-supplied data in the Microsoft SharePoint Server. A remote attacker can spoof page content.
2) Code Injection (CVE-ID: CVE-2021-34467)
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.
3) Code Injection (CVE-ID: CVE-2021-34468)
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 attacker on the local network 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.
4) Improper validation of integrity check value (CVE-ID: CVE-2021-34519)
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to missing integrity check on update downloads for SharePoint Help updates. A remote attacker can perform MitM attack and replace the files contents during update downloads.
5) Code Injection (CVE-ID: CVE-2021-34520)
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-2021-34517
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34467
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34468
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34519
- https://www.zerodayinitiative.com/advisories/ZDI-21-830/
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34520