Microsoft Security Response Center

**According to the CVSS metric, user interaction is required (UI:R) and privileges required are none (PR:N). What does that mean for this vulnerability?** An unauthorized attacker must wait for a user to initiate a connection.

**What type of information could be disclosed by this vulnerability?** An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory.

**Is there a prerequisite for installing the security update?** Yes. For **Windows Server 2012 R2 only**, to apply this update, you must have KB2919355 installed.

**According to the CVSS metrics, successful exploitation of this vulnerability does not impact confidentiality (C:N), but has major impact on integrity (I:H) and availability (A:H). What does that mean for this vulnerability?** Exploitation of this vulnerability does not disclose any confidential information but allows an attacker to modify or delete files containing data which could cause the service to become unavailable.

**What privileges could be gained by an attacker who successfully exploited this vulnerability?** An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

**How could an attacker exploit this vulnerability?** An attacker could exploit a use after free vulnerability within the OS SAPI component to execute arbitrary code in the context of the compromised user to disclose sensitive information, compromise system integrity or impact the availability of the victim's system.

**What does the security update provide to mitigate the risks associated with this vulnerability?** The security update will prevent untrusted Microsoft Saved Console (MSC) files from being opened to protect customers against the risks associated with this vulnerability.

**How could an attacker exploit this vulnerability?** An unauthenticated attacker could send a specially crafted protocol message to a Routing and Remote Access Service (RRAS) server, which could lead to remote code execution (RCE) on the RAS server machine.

**According to the CVSS metric, the attack vector is network (AV:N) and the user interaction is required (UI:R). What is the target context of the remote code execution?** This attack requires an admin user on the client to connect to a malicious server, and that could allow the attacker to gain code execution on the client.

**What privileges could be gained by an attacker who successfully exploited this vulnerability?** An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.