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Microsoft Excel Uninitialized Pointer Memory Corruption Vulnerability



Excel is the spreadsheet application included with Microsoft Corp.'s Office productivity software suite. More information is available at the following website:


Remote exploitation of a memory corruption vulnerability in Microsoft Corp.'s Excel, could allow attackers to execute arbitrary code with the privileges of the current user. Excel when processing a malformed file attempts to use a pointer which has never been initialized. This results in an exploitable situation.


Successful exploitation could allow an attacker to execute arbitrary code with the privileges of the user opening the file. The attacker can also cause a denial of service (DoS) condition. To exploit this vulnerability, the attacker must socially-engineer a user to open a specially crafted file. Attackers typically accomplish this by e-mailing a targeted user the file or hosting the file on a Web page. Note that attackers cannot exploit Office file format vulnerabilities in a drive-by manner; at a minimum, a targeted user must click an "open" dialog or choose to view an attachment. In this vulnerability, the attacker will also have to persuade the victim to click through the pop-up dialog box which Excel shows to the user when the user opens the exploit Excel file. When on the Windows platform, iDefense recommends configuring the affected application to use the exploitation mitigation methods that the Microsoft Corp. Enhanced Mitigation Experience Toolkit (EMET) tool provides. This will not prevent exploitation, but it will make it more complex on platforms that support data execution prevention (DEP) and address space layout randomization (ASLR). iDefense considers this vulnerability to be of MEDIUM-severity due to the possibility of arbitrary code execution, mitigated by the need for user interaction.


The following vendors include susceptible software within their respective software distributions:

  • Microsoft: excel 2010

    iDefense is unaware of any workaroundfor this vulnerability.


    Microsoft has released a fix which addresses this issue. For more information, consult their advisory at the following URL:


    The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2016-0136 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


    02/19/2016 Initial Vendor Notification
    02/19/2016 Initial Vendor Reply
    04/12/2016 Coordinated Public Disclosure


    This vulnerability was reported to iDefense by Steven Seeley of Source Incite .

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