This security advisory describes one high risk vulnerability.
CWE-200 - Information Exposure
The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.
The weakness exists due to an error in handling of a specially crafted response when opening a malicious Office file. A remote attacker can create a specially crafted file using, host it on remote website, trick the victim into opening it and gain access to tokens used to authenticate the current user on a targeted SharePoint or other Microsoft Office server site.
Successful exploitation of the vulnerability results in information disclosure on the vulnerable system.
Note: the vulnerability was being actively exploited.
Install update from vendor's website:
Microsoft Office 2013 (32-bit editions):
Microsoft Office 2013 (64-bit editions):
Microsoft Office: 2013CPE
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to trick the victim to visit a specially crafted website or open an attachment in an e-mail message.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.