SB2021051112 - Multiple vulnerabilities in Microsoft Exchange Server

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Main Vulnerability Database SB2021051112

SB2021051112 - Multiple vulnerabilities in Microsoft Exchange Server

Published: May 11, 2021 Updated: September 12, 2021

Security Bulletin ID SB2021051112
CSH Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 50% Medium 25% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Improper validation of integrity check value (CVE-ID: CVE-2021-31209)

CWE-ID: CWE-354 - Improper Validation of Integrity Check Value

CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass integrity checks.

The vulnerability exists within the handling of Exchange Server Help updates. A remote attacker on the local network can bypass integrity check on update downloads.

2) Security features bypass (CVE-ID: CVE-2021-31207)

CWE-ID: CWE-254 - Security Features

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear


The vulnerability allows a remote user to bypass authentication process.

The vulnerability exists due to security feature bypass issue in Microsoft Exchange Server. A remote administrator can gain full access to target system.


3) Code Injection (CVE-ID: CVE-2021-31198)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in Microsoft Exchange Server. A remote attacker can execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


4) Code Injection (CVE-ID: CVE-2021-31195)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in Microsoft Exchange Server. A remote attacker can execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Remediation

Install update from vendor's website.

References