MS-ISAC CYBERSECURITY ADVISORIES
MS-ISAC ADVISORY NUMBER:
Multiple Vulnerabilities in Windows Shell Could Allow Remote Code Execution (MS15-109)
Multiple vulnerabilities have been discovered in Windows Shell which could allow an attacker to take complete control of an affected system. The Windows Shell is used to run applications and manage the Windows operating system. Exploitation occurs when a user opens a specially crafted file designed to take advantage of this vulnerability. Successful exploitation of this vulnerability could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
There are currently no reports of these vulnerabilities being exploited in the wild.
Microsoft Windows Vista
Microsoft Windows 7
Microsoft Windows 8 and Windows 8.1
Microsoft Windows 10
Microsoft Windows RT and RT 8.1
Microsoft Windows Server 2008 and Server 2008 R2 (including Server Core installations)
Microsoft Windows Server 2012 and Server 2012 R2 (including Server Core installations)
Large and medium government entities: High
Small government entities: High
Large and medium business entities: High
Small business entities: High
Home users: High
Two use after free remote code execution vulnerabilities exist when Windows Shell fails to properly handle objects in memory. An attacker could exploit this vulnerability by constructing a specially crafted file and attempting to convince a user to open it from an email message or access it from a webpage. When the user opens the malicious file, Windows Shell fails to properly handle the objects in memory, allowing the attacker to execute arbitrary shell commands without the knowledge of the logged on user.
Successful exploitation of this vulnerability could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
We recommend the following actions be taken:
Deny access to the “TipBand.dll” as a workaround (CVE-2015-2548).
Apply appropriate patches provided by Microsoft to vulnerable systems immediately after appropriate testing.
Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources.