Multiple vulnerabilities in Microsoft SharePoint Server

1) Spoofing attack

EUVDB-ID: #VU54751

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34517

CWE-ID: CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of user-supplied data in the Microsoft SharePoint Server. A remote attacker can spoof page content.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2013 - 2019

Microsoft SharePoint Server: 2013

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34517

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

2) Code Injection

EUVDB-ID: #VU54755

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34467

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

Exploit availability: No

Description

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

The vulnerability exists due to improper input validation in the Microsoft SharePoint Server. A remote authenticated attacker can send a specially crafted request and execute arbitrary code on the target system.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2016 - 2019

Microsoft SharePoint Server: 2013

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34467

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

3) Code Injection

EUVDB-ID: #VU54754

Risk: Medium

CVSSv3.1: 6.2 [CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34468

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

Exploit availability: No

Description

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

The vulnerability exists due to improper input validation in the Microsoft SharePoint Server. A remote attacker on the local network can send a specially crafted request and execute arbitrary code on the target system.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2016 - 2019

Microsoft SharePoint Server: 2013

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34468

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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

4) Improper validation of integrity check value

EUVDB-ID: #VU54753

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34519

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to missing integrity check on update downloads for SharePoint Help updates. A remote attacker can perform MitM attack and replace the files contents during update downloads.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2013 - 2016

Microsoft SharePoint Foundation: 2013

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34519
http://www.zerodayinitiative.com/advisories/ZDI-21-830/

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

5) Code Injection

EUVDB-ID: #VU54752

Risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34520

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

Exploit availability: No

Description

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

The vulnerability exists due to improper input validation in the Microsoft SharePoint Server. A remote authenticated attacker can send a specially crafted request and execute arbitrary code on the target system.

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

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2016 - 2019

Microsoft SharePoint Server: 2013

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34520

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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