SB2018071010 - Multiple vulnerabilities in Microsoft SharePoint Server

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2018-8323)

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. A remote attacker 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.

2) Cross-site scripting (CVE-ID: CVE-2018-8299)

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. A remote attacker 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.

3) Improper input validation (CVE-ID: CVE-2018-8300)

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

The vulnerability exists due to improper check of the source markup of an application package. A remote unauthenticated attacker can trick the victim into uploading a specially crafted SharePoint application package to an affected versions of SharePoint and run arbitrary code in the context of the SharePoint application pool and the SharePoint server farm account.

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

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8323
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8299
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8300