Microsoft Office CTaskSymbol Use-After-Free Vulnerability

An use-after-free vulnerability (CVE-2015-1642) was discovered as the affected application improperly handles the CTaskSymbol COM object in memory while parsing a crafted Office file. If persuaded to open the crafted Office file, a successful exploitation would allow an attacker to run arbitrary code in the context of the victim.

Microsoft Office is a suite of desktop applications consisting of Word, Powerpoint, Excel, Outlook and various other productivity applications. The applications are affected by a use-after-free vulnerability while parsing a specially crafted Office file as a result of the application loading the CTaskSymbolCOM object in memory.

If persuaded to open the crafted Office file, a successful exploitation would allow an attacker to run arbitrary code in the context of the target application.

The vulnerability exists because Microsoft Office incorrectly dereferences the CTaskSymbol object after it is freed.

Avoid opening Office files from untrusted sources or view them in Protected-View mode.

Users should apply MS15-081 updates from Microsoft.

Refer to attached detailed advisory above.