#Security Vulnerability

**According to the CVSS score, the attack vector is Local. 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.

**In what scenarios is my computer vulnerable?** For Windows 11 and Windows 10 the FAX service is not installed by default. To exploit this vulnerability, the Windows Fax and Scan feature needs to be enabled, and the Fax service needs to be running. Systems that do not have the Fax service running are not vulnerable. **How can I verify whether the Fax service is running?** 1. Hold the **Windows key** and press **R** on your keyboard. This will open the Run dialog. 2. Type _services.msc_ and press **Enter** to open the Services window. 3. Scroll through the list and locate the **Fax** service. * If the Fax service is not listed, Windows Fax and Scan is not enabled and the system is not vulnerable. * If the Fax service is listed but the status is not _Running_, then the system is not vulnerable at the time, but could be targeted if the service was started. The update should be installed as soon as possible or the Fax service should be removed if not needed.

**In what scenarios is my computer vulnerable?** For Windows 11 and Windows 10 the FAX service is not installed by default. To exploit this vulnerability, the Windows Fax and Scan feature needs to be enabled, and the Fax service needs to be running. Systems that do not have the Fax service running are not vulnerable. **How can I verify whether the Fax service is running?** 1. Hold the **Windows key** and press **R** on your keyboard. This will open the Run dialog. 2. Type _services.msc_ and press **Enter** to open the Services window. 3. Scroll through the list and locate the **Fax** service. * If the Fax service is not listed, Windows Fax and Scan is not enabled and the system is not vulnerable. * If the Fax service is listed but the status is not _Running_, then the system is not vulnerable at the time, but could be targeted if the service was started. The update should be installed as soon as possible or the Fax service should be removed if not needed.

**In what scenarios is my computer vulnerable?** For Windows 11 and Windows 10 the FAX service is not installed by default. To exploit this vulnerability, the Windows Fax and Scan feature needs to be enabled, and the Fax service needs to be running. Systems that do not have the Fax service running are not vulnerable. **How can I verify whether the Fax service is running?** 1. Hold the **Windows key** and press **R** on your keyboard. This will open the Run dialog. 2. Type _services.msc_ and press **Enter** to open the Services window. 3. Scroll through the list and locate the **Fax** service. * If the Fax service is not listed, Windows Fax and Scan is not enabled and the system is not vulnerable. * If the Fax service is listed but the status is not _Running_, then the system is not vulnerable at the time, but could be targeted if the service was started. The update should be installed as soon as possible or the Fax service should be removed if not needed.

**I am running a supported version of Windows Server. Is my system vulnerable to this issue?** This vulnerability is only exploitable for systems that have the NFS role enabled. See NFS Overview for more information on this feature. More information on installing or uninstalling Roles or Role Services is available here.

**What privileges does an attacker require to exploit this vulnerability?** Exploiting this vulnerability requires an attacker to compromise admin credentials to the replication appliance, configuration server, or one of the VMs associated with the configuration server.

**According to the CVSS, User Interaction is Required. What interaction would the user have to do?** This vulnerability requires that a user with an affected version of Windows access a malicious server. An attacker would have to host a specially crafted server share or website. An attacker would have no way to force users to visit this specially crafted server share or website, but would have to convince them to visit the server share or website, typically by way of an enticement in an email or chat message.

**According to the CVSS, User Interaction is Required. What interaction would the user have to do?** This vulnerability requires that a user with an affected version of Windows access a malicious server. An attacker would have to host a specially crafted server share or website. An attacker would have no way to force users to visit this specially crafted server share or website, but would have to convince them to visit the server share or website, typically by way of an enticement in an email or chat message.

**How could an attacker exploit this vulnerability?** In order to exploit this vulnerability the attacker is required to be a local user with a smart card or already logged on remotely through RDP to the remote machine. The authorized attacker could then exploit this Windows LSASS vulnerability by sending, from a user mode application, specially crafted malicious credentials directed at the Windows machine, which could lead to remote code execution.

**How could an attacker exploit the vulnerability?** To exploit this vulnerability, an attacker would need to trick a user into executing a specially crafted script which executes an RPC call to an RPC host. This could result in remote code execution on the server side with the same permissions as the RPC service.