SRC-2016-0038 : Microsoft Office Excel EOF Record Type Confusion Remote Code Execution Vulnerability

CVE ID:

CVE-2016-3363

CVSS Score:

9.3, (AV:N/AC:M/Au:N/C:C/I:C/A:C)

Affected Vendors:

Microsoft

Affected Products:

Office Excel

  • Microsoft Excel 2007 Service Pack 3
  • Microsoft Excel 2010 Service Pack 2 (32-bit editions)
  • Microsoft Excel 2010 Service Pack 2 (64-bit editions)
  • Microsoft Excel 2013 Service Pack 1 (32-bit editions)
  • Microsoft Excel 2013 Service Pack 1 (64-bit editions)
  • Microsoft Excel 2013 RT Service Pack 1
  • Microsoft Excel 2016 (32-bit edition)
  • Microsoft Excel 2016 (64-bit edition)
  • Microsoft Office Compatibility Pack Service Pack 3
  • Microsoft Excel Viewer

Vulnerability Details:

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Office Excel. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the handling of an EOF Record. The type value of the allocated object is not checked before being used in an operation leading to an Out-of-Bounds read condition. An attacker can leverage this vulnerability to execute arbitrary code under the context of the current process.

Vendor Response:

Microsoft has issued an update to correct this vulnerability. More details can be found at: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2016-3363

Disclosure Timeline:

  • 2016-06-29 – Vulnerability reported to vendor
  • 2016-09-13 – Coordinated public release of advisory

Proof of Concept:

https://github.com/sourceincite/poc/blob/master/SRC-2016-0038.xls

Credit:

This vulnerability was discovered by Steven Seeley of Source Incite