Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
According to the CVSS metric, the attack vector is adjacent (AV:A). What does that mean for this vulnerability? This vulnerability's attack is limited at the protocol level to a logically adjacent topology. This means it cannot simply be done across the internet, but instead needs something specific tied to the target. Good examples would include the same shared physical network (such as Bluetooth or IEEE 802.11), logical network (local IP subnet), or from within a secure or otherwise limited administrative domain (MPLS, secure VPN to an administrative network zone). This is common to many attacks that require machine-in-the-middle (MITM) type setups or that rely on initially gaining a foothold in another environment. According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? The attacker must inject themselves into the logical network path between the target and the resource requested by the victim to read or modify network communications. This is called a machine-in-the-middle (MITM) attack.
Malcolm Stagg with <a href="https://www.sodium24.com/">SODIUM-24, LLC</a>