#Security Vulnerability

**According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?** The word **Remote** in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. For example, when the score indicates that the **Attack Vector** is **Local** and **User Interaction** is **Required**, this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and open a specially crafted file from a website which leads to a local attack on their computer.

**According to the CVSS metrics, successful exploitation of this vulnerability could lead to minor loss of confidentiality (C:L), integrity (I:L) and availability (A:L). What does that mean for this vulnerability?** While we cannot rule out the impact to Confidentiality, Integrity, and Availability, the ability to exploit this vulnerability by itself is limited. An attacker would need to combine this with other vulnerabilities to perform an attack.

**According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?** Successful exploitation of this vulnerability requires an attacker to prepare the target environment to improve exploit reliability.

**According to the CVSS metric, privileges required is low (PR:L). Does the attacker need to be in an authenticated role on the Exchange Server?** Yes, the attacker must be authenticated.

**According to the CVSS metric, privileges required is low (PR:L). What does that mean for this vulnerability?** Any authenticated attacker could trigger this vulnerability. It does not require admin or other elevated privileges.

**According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?** Successful exploitation of this vulnerability requires an attacker to win a race condition.

**Is the Preview Pane an attack vector for this vulnerability?** No, the Preview Pane is not an attack vector.

**According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?** An attacker must send the user a malicious file and convince the user to open said file.

**According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?** Successful exploitation of this vulnerability requires an attacker to take additional actions prior to exploitation to prepare the target environment.

A remote code execution vulnerability exists when Microsoft .NET Framework fails to properly validate input before loading libraries. An attacker who successfully exploited this vulnerability could take control of an 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. To exploit the vulnerability, an attacker would first need to access the local system with the ability to execute a malicious application. The security update addresses the vulnerability by correcting how .NET validates input on library load.