September 2015 Patch Tuesday

September’s Patch Tuesday offers 12 bulletins which include the typical round of Internet Explorer and Office updates. Windows 10’s new browser, Edge, also receives its second consecutive round of updates, however with much fewer vulnerabilities being addressed when compared to IE, indicating that it is indeed more secure than its predecessor. Similar to last month, many Font Processing flaws are resolved, showing a definite trend within the threat landscape that security researchers are pursing. MS15-094: Cumulative Security Update for Internet Explorer (3089548) Internet Explorer gets its monthly dose of fixes and is patched for 17 vulnerabilities, 14 of which can allow remote code execution. The remaining vulnerabilities include the typical Elevation of Privilege, Information Disclosure, and a not so common one – Tampering (CVE-2015-2484, which occurs when IE accesses a file with an improper flag that in turn permits file operations. If successfully exploited, an attacker can delete arbitrary files on the affected system. MS15-095: Cumulative Security Update for Microsoft Edge (3089665) Microsoft Edge receives another round of patches with only 4 critical-rated remote code execution vulnerabilities being fixed. Prior to the bulletins release, there were no reports of these vulnerabilities being exploited in the wild and they were privately disclosed. MS15-096: Vulnerability in Active Directory Service Could Allow Denial of Service (3072595) This bulletin addresses a Denial of Service vulnerability within Active Directory when an authenticated attacker creates multiple machine accounts. To exploit this vulnerability, an attacker must have a privileged account to join machines to the domain, limiting the attack surface. MS15-097: Vulnerabilities in Microsoft Graphics Component Could Allow Remote Code Execution (3089656) Font parsing vulnerabilities strike again! This bulletin resolves 11 vulnerabilities with the majority allowing Elevation of Privileges. CVE-2015-2510 is, however, a critical buffer overflow vulnerability which can lead to remote code execution. Reported by Steven Vittitoe of Google Project Zero, CVE-2015-2510 can be exploited by tricking a user to view a specially crafted webpage containing embedded OpenType Fonts or by opening a document from within Windows, Office, or Lync. MS15-098: Vulnerabilities in Windows Journal Could Allow Remote Code Execution (3089669) Windows Journal is patched for 4 critical remote code execution vulnerabilities, one of which (CVE-2015-2513) was discovered and reported by Phil Blankenship of BeyondTrust’s own research team. These vulnerabilities are caused by Journal mishandling crafted .jnt files, allowing an attacker to execute code in the context of the current user. There is no way to force a victim to view a malicious .jnt file, so a bit social engineering is required on the attacker’s part. MS15-099: Vulnerabilities in Microsoft Office Could Allow Remote Code Execution (3089664) Patch Tuesday just wouldn’t be complete without a few Office fixes, right? This bulletin resolves 4 remote code execution vulnerabilities and a good old fashioned persistent Cross-site Scripting vulnerability within Sharepoint. The remote code execution vulnerabilities lie mostly within Excel, however, documents with embedded post script can also lead to memory corruption. MS15-100: Vulnerability in Windows Media Center Could Allow Remote Code Execution (3087918) Windows Media Center is patched for a vulnerability that occurs upon opening a specially crafted Media Center link (.mcl) file, allowing for remote code execution in the context of the current user. In order to exploit this vulnerability, an attacker would have to find a way to plant the .mcl file on the local machine which can then be executed to run applications from an attacker-controlled location. MS15-101: Vulnerabilities in .NET Framework Could Allow Elevation of Privilege (3089662) This bulletin resolves two vulnerabilities which can allow Elevation of Privileges or a Denial of Service. The EoP vulnerability (which was publically disclosed prior to this bulletins release) can be exploited through either a web browsing attack, where an attacker would host a specially crafted website that the victim browses to, or through a .NET application attack, where the malicious application is programmed to bypass Code Access Security (CAS) restrictions which the victim unknowingly executes. MS15-102: Vulnerabilities in Windows Task Management Could Allow Elevation of Privilege (3089657) Task Management is patched for 3 Elevation of Privilege vulnerabilities which an attacker can use in conjunction with code execution vulnerabilities in order to take complete control of the system. To exploit these EoP vulnerabilities, an attacker would need a way to get a malicious executable onto the system and then execute it. MS15-103: Vulnerabilities in Microsoft Exchange Server Could Allow Information Disclosure (3089250) This bulletin resolves an information disclosure vulnerability and two spoofing vulnerabilities within Microsoft Exchange Server. The information disclosure vulnerability occurs when Outlook Web Access fails to properly handle web requests, which could allow an attacker to discover stacktrace details, aiding them in exploit development. The two spoofing vulnerabilities occur when an attacker sends a specially crafted email to the victim, allowing HTML injection attacks. MS15-104: Vulnerabilities in Skype for Business Server and Lync Server Could Allow Elevation of Privilege (3089952) Skype for Business and Lync Server are patched for 3 Cross-site Scripting vulnerabilities which can allow elevation of privilege and information disclosure. All of these vulnerabilities are exploited through specially crafted URL’s in which the victim must click. Typical attack scenarios include phishing emails or by visiting a malicious website which convinces the victim to click the URL. MS15-105: Vulnerability in Windows Hyper-V Could Allow Security Feature Bypass (3091287) And finally, this bulletin address a single vulnerability within Hyper-V which can allow unintended traffic to be transmitted. The issue only exists when access control list (ACL) configuration settings are not applied correctly and in order to exploit, an attacker would need to run a specially crafted application on the affected system.