PT-2021-5689 · Microsoft · Sharepoint Server+1

Published 2021-03-26 · Updated 2023-12-28 · CVE-2021-34520

Positive Technologies (AI Summary)

CVSS v2.0

9.0

High

Base vector

AV:N/AC:L/Au:S/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Microsoft SharePoint Server (affected versions not specified)

Description The issue is related to the implementation of the Microsoft.SharePoint.WorkflowActions.SetVariableActivity class in Microsoft SharePoint Foundation, SharePoint Server, and SharePoint Enterprise Server. It involves the deserialization of untrusted data, allowing an attacker to recover in memory an instance of an arbitrary .NET type by adding a SetVariableActivity element. This can enable a remote attacker to execute arbitrary code. The vulnerability affects Microsoft SharePoint Server, allowing remote attackers to execute arbitrary code and impact the system.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Deserialization of Untrusted Data

Weakness Enumeration

CWE-502

Related Identifiers

BDU:2022-00128

CVE-2021-34520

ZDI-21-828

Affected Products

Sharepoint Foundation

Sharepoint Server

References · 8

• https://bdu.fstec.ru/vul/2022-00128 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-34520 · Security Note
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34520 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-34520 · Security Note
• https://zerodayinitiative.com/advisories/ZDI-21-828 · Security Note
• https://osv.dev/vulnerability/CVE-2021-34520 · Vendor Advisory
• https://t.me/cvenotify/17838 · Telegram Post
• https://t.me/cvenotify/17775 · Telegram Post