Multiple vulnerabilities in Microsoft SharePoint Server

1) Cross-site scripting

EUVDB-ID: #VU102660

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21393

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2019

Microsoft SharePoint Server Subscription Edition: All versions

Microsoft SharePoint Enterprise Server: 2016

CPE2.3

• cpe:2.3:a:microsoft:microsoft_sharepoint_server:2019:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_server_subscription_edition:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_enterprise_server:2016:*:*:*:*:*:*:*

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21393

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.

2) Improper Authorization

EUVDB-ID: #VU102664

Risk: Low

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21348

CWE-ID: CWE-285 - Improper Authorization

Exploit availability: No

Description

The vulnerability allows a remote user to bypass authorization checks.

The vulnerability exists due to insufficient authorization controls in Microsoft SharePoint Server. A remote administrator can execute arbitrary code on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2019

Microsoft SharePoint Server Subscription Edition: All versions

Microsoft SharePoint Enterprise Server: 2016

CPE2.3

• cpe:2.3:a:microsoft:microsoft_sharepoint_server:2019:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_server_subscription_edition:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_enterprise_server:2016:*:*:*:*:*:*:*

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21348

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

3) Input validation error

EUVDB-ID: #VU102662

Risk: High

CVSSv4.0: 6.1 [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]

CVE-ID: CVE-2025-21344

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input in Microsoft SharePoint Server. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2019

Microsoft SharePoint Server Subscription Edition: All versions

Microsoft SharePoint Enterprise Server: 2016

CPE2.3

• cpe:2.3:a:microsoft:microsoft_sharepoint_server:2019:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_server_subscription_edition:*:*:*:*:*:*:*:*
• cpe:2.3:a:microsoft:microsoft_sharepoint_enterprise_server:2016:*:*:*:*:*:*:*

External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21344

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.