SB2019111212 - Multiple vulnerabilities in Microsoft SharePoint

Description

This security bulletin contains information about 2 vulnerabilities.

1) Arbitrary file upload (CVE-ID: CVE-2019-1443)

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

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

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to the way SharePoint server handles file uploads. A remote authenticated user can upload a specially crafted file to the server and use it to obtain SMB hashes.

2) Spoofing attack (CVE-ID: CVE-2019-1442)

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

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

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of certain URLs. A remote attacker can create a specially crafted file, force the victim into opening it and then trick a victim into entering credentials that can be obtained by the attacker.

Successful exploitation of the vulnerability may allow to conduct a phishing attack.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1443
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1442