#Security Vulnerability

**Why is this Red Hat, Inc. CVE included in the Security Update Guide?** The vulnerability assigned to this CVE is in Linux Shim boot. It is being documented in the Security Update Guide to announce that the latest builds of Microsoft Windows address this vulnerability by blocking old, unpatched, Linux boot loaders by applying SBAT (Secure Boot Advanced Targeting) EFI variables in the UEFI library. Please see Security Update Guide Supports CVEs Assigned by Industry Partners for more information. For more information see: CVE-2023-40547.

**The following mitigating factors might be helpful in your situation:** * Users are advised against installing or enabling the Line Printer Daemon (LPD) service. * The LPD is not installed or enabled on the systems by default. * The LPD has been announced as deprecated since Windows Server 2012. Please refer to: Features Removed or Deprecated in Windows Server 2012.

**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.

**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.

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

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

**According to the CVSS metric, successful exploitation of this vulnerability could lead to some loss of confidentiality (C:L) and integrity (I:L) but does not impact availability (A:N)? What does that mean for this vulnerability?** The attacker is only able to modify the sender's name of Teams message (I:L) and through social engineering, attempt to trick the recipient into disclosing information (C:L). The availability of the product cannot be affected (A:N).

**What privileges could be gained by an attacker who successfully exploited the vulnerability?** An attacker could use this vulnerability to elevate privileges from a Low Integrity Level in a contained ("sandboxed") execution environment to a Medium Integrity Level or a High Integrity Level. Please refer to AppContainer isolation and Mandatory Integrity Control for more information.

**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 authenticated client to click a link in order for an unauthenticated attacker to initiate remote code execution.

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