Multiple vulnerabilities in Microsoft Exchange Server



Published: 2021-03-03 | Updated: 2021-03-11
Risk Critical
Patch available YES
Number of vulnerabilities 7
CVE-ID CVE-2021-26412
CVE-2021-26854
CVE-2021-26855
CVE-2021-26857
CVE-2021-26858
CVE-2021-27065
CVE-2021-27078
CWE-ID CWE-20
CWE-918
Exploitation vector Network
Public exploit Vulnerability #3 is being exploited in the wild.
Vulnerability #4 is being exploited in the wild.
Vulnerability #5 is being exploited in the wild.
Vulnerability #6 is being exploited in the wild.
Vulnerable software
Subscribe
Microsoft Exchange Server
Server applications / Mail servers

Vendor Microsoft

Security Bulletin

This security bulletin contains information about 7 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU51174

Risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26412

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.


Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26412

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Input validation error

EUVDB-ID: #VU51173

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-26854

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.


Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26854

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Server-Side Request Forgery (SSRF)

EUVDB-ID: #VU51171

Risk: Critical

CVSSv3.1: 9.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-26855

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted HTTP request to the Microsoft Exchange OWA interface, upload arbitrary file on the server and execute it.

Note, this vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855
http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server
http://github.com/microsoft/CSS-Exchange/tree/main/Security

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

4) Input validation error

EUVDB-ID: #VU51170

Risk: Critical

CVSSv3.1: 8.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-26857

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.

Note, this vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857
http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

5) Input validation error

EUVDB-ID: #VU51169

Risk: Critical

CVSSv3.1: 8.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-26858

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.

Note, this vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26858
http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

6) Input validation error

EUVDB-ID: #VU51168

Risk: Critical

CVSSv3.1: 8.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-27065

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.

Note, this vulnerability is being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27065
http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

7) Input validation error

EUVDB-ID: #VU51172

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-27078

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.


Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013, 2013 Cumulative Update 1, 2013 Cumulative Update 2, 2013 Cumulative Update 3, 2013 Cumulative Update 4, 2013 Cumulative Update 5, 2013 Cumulative Update 6, 2013 Cumulative Update 7, 2013 Cumulative Update 8, 2013 Cumulative Update 9, 2013 Cumulative Update 10, 2013 Cumulative Update 11, 2013 Cumulative Update 12, 2013 Cumulative Update 13, 2013 Cumulative Update 14, 2013 Cumulative Update 15, 2013 Cumulative Update 16, 2013 Cumulative Update 17, 2013 Cumulative Update 18, 2013 Cumulative Update 19, 2013 Cumulative Update 20, 2013 Cumulative Update 21, 2013 Cumulative Update 22, 2013 Cumulative Update 23, 2013 Service Pack 1, 2016, 2016 Cumulative Update 1, 2016 Cumulative Update 2, 2016 Cumulative Update 3, 2016 Cumulative Update 4, 2016 Cumulative Update 5, 2016 Cumulative Update 6, 2016 Cumulative Update 7, 2016 Cumulative Update 8, 2016 Cumulative Update 9, 2016 Cumulative Update 10, 2016 Cumulative Update 11, 2016 Cumulative Update 12, 2016 Cumulative Update 13, 2016 Cumulative Update 14, 2016 Cumulative Update 15, 2016 Cumulative Update 16, 2016 Cumulative Update 17, 2016 Cumulative Update 18, 2016 Cumulative Update 19, 2019, 2019 Cumulative Update 1, 2019 Cumulative Update 2, 2019 Cumulative Update 3, 2019 Cumulative Update 4, 2019 Cumulative Update 5, 2019 Cumulative Update 6, 2019 Cumulative Update 7, 2019 Cumulative Update 8

CPE2.3 External links

http://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27078

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



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