SB2018121104 - Multiple vulnerabilities in Microsoft SharePoint

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Privilege escalation (CVE-ID: CVE-2018-8635)

The vulnerability allows a remote authenticated attacker to gain elevated privileges on the target system.

The weakness exists due to improper sanitization of a specially crafted authentication request to an affected SharePoint server. A remote attacker can send a specially crafted message to perform a server-side request forgery attack and execute malicious code on a vulnerable server in the context of the SharePoint application pool account.

Successful exploitation of the vulnerability may result in system compromise.

2) Cross-site search attacks (CVE-ID: CVE-2018-8580)

The vulnerability allows a remote authenticated attacker to perform cross-site search attacks.

The weakness exists due to insufficient CSRF protections in certain modes of the search function in Microsoft SharePoint Server. A remote attacker can create a specially crafted HTML page or URL, trick the victim into visiting it, induce the browser to invoke search queries as the logged in user through standard browser functionality to determine whether the query did return results or not, and thus by issuing targeted queries discover facts about documents that are searchable for the logged-in user.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8635
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8580