Microsoft SharePoint Missing Check of Message Integrity Vulnerability

2021-07-1900:00:00

mr_me

www.zerodayinitiative.com

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

2.3 Low

CVSS2

Access Vector

ADJACENT_NETWORK

Access Complexity

MEDIUM

Authentication

SINGLE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:A/AC:M/Au:S/C:N/I:P/A:N

0.633 Medium

EPSS

Percentile

97.8%

JSON

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.