==================================================================== CERT-Renater Note d'Information No. 2016/VULN325 _____________________________________________________________________ DATE : 14/09/2016 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running Microsoft Office versions 2007, 2010, 2013, 2016, for Mac 2011, 2016 for Mac, Microsoft Office Compatibility Pack, Microsoft Excel Viewer, Microsoft PowerPoint Viewer, Microsoft Word Viewer. ===================================================================== KB3185852 https://technet.microsoft.com/en-us/library/security/MS16-107 ____________________________________________________________________ Microsoft Security Bulletin MS16-107: Critical Security Update for Microsoft Office (3185852) Executive Summary This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights. Affected Software Microsoft Office 2007 Microsoft Office 2010 Microsoft Office 2013 Microsoft Office 2013 RT Microsoft Office 2016 Microsoft Office for Mac 2011 Microsoft Office 2016 for Mac Microsoft Office Compatibility Pack Service Pack 3 Microsoft Office Compatibility Pack Service Pack 3 Microsoft Excel Viewer Microsoft PowerPoint Viewer Microsoft Word Viewer Vulnerability Information Microsoft APP-V ASLR Bypass - CVE-2016-0137 An information disclosure vulnerability exists in the way that the Click-to-Run (C2R) components handle objects in memory, which could lead to an Address Space Layout Randomization (ASLR) bypass. An attacker who successfully exploited the information disclosure vulnerability could use the obtained information to bypass the ASLR security mechanism in Windows, which helps protect users from a broad class of vulnerabilities. The ASLR bypass by itself does not allow arbitrary code execution; however, an attacker could use the ASLR bypass in conjunction with another vulnerability, such as a remote code execution vulnerability, that could leverage the ASLR bypass to run arbitrary code. To exploit the ASLR bypass, an attacker would have to log on to an affected system and run a specially crafted application. Workstations are primarily vulnerable to the potential ASLR bypass. The security update addresses the ASLR bypass by correcting how C2R components handle memory addresses. The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list: Vulnerability title CVE number Publicly disclosed Exploited Microsoft APP-V ASLR Bypass CVE-2016-0137 No No Microsoft Information Disclosure Vulnerability - CVE-2016-0141 An information disclosure vulnerability exists when Visual Basic macros in Office improperly exports a users private key from the certificate store while saving a document. An attacker who successfully exploited the vulnerability could potentially gain access to the users private key. The attacker would have to use another vulnerability, or employ a social engineering technique, to obtain the saved document from the user. The security update addresses the vulnerability by correcting how Microsoft Office saves documents. The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list: Vulnerability title CVE number Publicly disclosed Exploited Microsoft Information Disclosure Vulnerability CVE-2016-0141 No No Multiple Microsoft Office Memory Corruption Vulnerabilities Multiple remote code execution vulnerabilities exist in Microsoft Office software when the Office software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerabilities requires that a user open a specially crafted file with an affected version of Microsoft Office software. In an email attack scenario an attacker could exploit the vulnerabilities by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file that is designed to exploit the vulnerabilities. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or Instant Messenger message, and then convince them to open the specially crafted file. Note that where the severity is indicated as Critical in the Affected Software and Vulnerability Severity Ratings table, the Preview Pane is an attack vector for CVE-2016-3357. The security update addresses the vulnerabilities by correcting how Microsoft Office handles objects in memory. The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list: Vulnerability title CVE number Publicly disclosed Exploited Microsoft Office Memory Corruption Vulnerability CVE-2016-3357 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3358 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3359 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3360 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3361 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3362 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3363 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3364 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3365 No No Microsoft Office Memory Corruption Vulnerability CVE-2016-3381 No No Microsoft Office Spoofing Vulnerability - CVE-2016-3366 A spoofing vulnerability exists when Microsoft Outlook does not strictly adhere to RFC2046, and improperly identifies the end of a MIME attachment. An improper MIME attachment ending may cause antivirus or antispam scanning to not work as intended. To exploit the vulnerability, an attacker could send a specially crafted email attachment to a user in an attempt to launch a social engineering attack, such as phishing. The security update addresses the vulnerability by correcting how Outlook determines the end of MIME messages. The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list: Vulnerability title CVE number Publicly disclosed Exploited Microsoft Office Spoofing Vulnerability CVE-2016-3366 No No ========================================================== Serveur de référence du CERT-Renater https://services.renater.fr/ssi/ ========================================================== + CERT-RENATER | tel : 01-53-94-20-44 + + 23 - 25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email: cert@support.renater.fr + ==========================================================