Microsoft Security Response Center

**According to the CVSS metrics, Confidentiality, Integrity, and Availability are Low (C:L, I:L, A:L). What would attacker have to do to exploit 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 can force a bad response to be cached into a regular URL by having multiple occurrences of the same variable in the query string. The impact depends on the business logic of the user application.

**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 complexity is high (AC:H). What does that mean for this vulnerability?** Successful exploitation of this vulnerability requires an attacker to invest time in repeated exploitation attempts through sending constant or intermittent data.

**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 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.

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

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

**How could an attacker exploit this vulnerability?** This vulnerability could be exploited over the network by making an unauthenticated, specially crafted call to a Network File System (NFS) service to trigger a Remote Code Execution (RCE).

**What type of information could be disclosed by this vulnerability?** The type of information that could be disclosed if an attacker successfully exploited this vulnerability is uninitialized memory.

**In what scenarios is my computer vulnerable?** For Windows 11 and Windows 10 the FAX service is not installed by default. For the vulnerability to be exploitable, 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.