PT-2021-4397 · Microsoft · Sharepoint Server+1

Published 2021-10-12 · Updated 2023-08-01 · CVE-2021-40487

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) Microsoft SharePoint Foundation (affected versions not specified) Microsoft SharePoint Enterprise Server (affected versions not specified)

Description The issue is related to incorrect code generation management in Microsoft SharePoint products. It allows a remote attacker to execute arbitrary code. The vulnerability can be exploited by deserializing untrusted data in the SetVariableActivity.

Recommendations For Microsoft SharePoint Server, consider restricting access to the SetVariableActivity deserialization functionality until a patch is available. For Microsoft SharePoint Foundation, restrict access to potentially vulnerable components to minimize the risk of exploitation. For Microsoft SharePoint Enterprise Server, avoid using untrusted data in deserialization processes until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

RCE

Code Injection

Weakness Enumeration

CWE-94

Related Identifiers

BDU:2021-05027

CVE-2021-40487

ZDI-21-1225

Affected Products

Sharepoint Server

Sharepoint Foundation

References · 11

• https://zerodayinitiative.com/advisories/ZDI-21-1225 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-40487 · Security Note
• https://bdu.fstec.ru/vul/2021-05027 · Security Note
• https://osv.dev/vulnerability/CVE-2021-40487 · Vendor Advisory
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40487 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-40487 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-40487 · Security Note
• https://t.me/true_secator/2209 · Telegram Post
• https://t.me/isacarusec/4535 · Telegram Post
• https://cybersecurity-help.cz/vdb/SB2021101210 · Note
• https://t.me/cibsecurity/30491 · Telegram Post