Vulnerability identifier: #VU5563

Vulnerability risk: High

CVSSv3.1: 8.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2015-2521

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Microsoft Excel
Client/Desktop applications / Office applications

Vendor: Microsoft

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

The vulnerability exists due to boundary error when processing Excel documents. A remote attacker can create a specially crafted Excel file, trick the victim into opening it, cause memory corruption and execute arbitrary code with privileges of the current user.

Successful exploitation of this vulnerability results in arbitrary code execution on the vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Microsoft Excel:

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External links
http://technet.microsoft.com/en-us/library/security/ms15-099

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.