CVE-2021-34519: Microsoft SharePoint Missing Check of Message Integrity Vulnerability
Microsoft SharePoint Server Information Disclosure Vulnerability
Other sources
This vulnerability allows network-adjacent attackers to tamper with update data on affected installations of Microsoft SharePoint. User interaction is required to exploit this vulnerability. The specific flaw exists within the handling of SharePoint Help updates. The issue results from a missing integrity check on update downloads. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the service account.
— ZDI
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.0.5363.1000Patch KB5001996 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5188.1000Patch KB5001981 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.0.5363.1000Patch KB5001984
Event History
Frequently Asked Questions
What is CVE-2021-34519 vulnerability?
CVE-2021-34519 is a vulnerability in Microsoft SharePoint that allows network-adjacent attackers to tamper with update data.
How can an attacker exploit CVE-2021-34519 vulnerability?
An attacker requires user interaction to exploit CVE-2021-34519 by tampering with SharePoint Help updates.
What is the severity of CVE-2021-34519 vulnerability?
The severity of CVE-2021-34519 vulnerability is low with a CVSS severity score of 3.5.
Which versions of Microsoft SharePoint are affected by CVE-2021-34519 vulnerability?
Microsoft SharePoint Foundation 2013 SP1, Microsoft SharePoint Server 2013 SP1, and Microsoft SharePoint Server 2016 are affected by CVE-2021-34519 vulnerability.
How can I learn more about CVE-2021-34519 vulnerability?
You can find more information about CVE-2021-34519 vulnerability on the Microsoft Security Response Center (MSRC) website.