PT-2021-2212 · Microsoft · Exchange Server

Published 2021-03-02 · Updated 2026-05-04 · CVE-2021-26858

Positive Technologies (AI Summary)

CVSS v2.0

10

High

Base vector

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

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

Description The issue is related to insufficient input validation in Microsoft Exchange Server, which can be exploited by a remote attacker to overwrite arbitrary files in the system. This allows remote attackers to execute arbitrary code.

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

RCE

Weakness Enumeration

CWE-20

Related Identifiers

BDU:2021-01121

CVE-2021-26858

Affected Products

Exchange Server

References · 64

• https://nvd.nist.gov/vuln/detail/CVE-2021-26858 · Security Note
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26858 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-01121 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26858 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-26858 · Vendor Advisory
• https://t.me/cvenotify/10767 · Telegram Post
• https://t.me/cvenotify/10771 · Telegram Post
• https://t.me/aptreports/1788 · Telegram Post
• https://t.me/cvenotify/87459 · Telegram Post
• https://t.me/sysadm_in_channel/2837 · Telegram Post
• https://t.me/cibsecurity/24376 · Telegram Post
• https://t.me/aptreports/22232 · Telegram Post
• https://t.me/aptreports/23574 · Telegram Post
• https://t.me/cibsecurity/24381 · Telegram Post
• https://t.me/aptreports/1615 · Telegram Post