## 7 Discussion of the Filtering Impact on Security and Privacy
### Influence of Filtering on STRIDE Attack Vectors
In any case, if an attacker sends malicious ARP replies to a victim that should not be accessible, the victim may not be able to send messages back to the attacker if that communication is also not allowed. Furthermore, the attacker may not have permission to forward the messages themselves (e.g., if the victim has access to server A but the attacker does not). Therefore, even in the case of a successful ARP spoofing attack, an attacker may not be able to become a man in the middle. Overall, the impact of this sub-vector is considered to be medium, although the effectiveness depends highly on the scenario, as just discussed. While the situation is not as clear for ARP spoofing, it is much easier for DHCP spoofing. Since the DHCP server is on the home router itself, there is no need to give any client permission to send DHCP solicitations. Therefore, it is assumed that there is a _high_ impact on this sub-vector. The effect on Evil Twin attacks has already been rated as _some_ influence in the _MME_ paragraph above. Overall, the effect for this vector is rated as _medium_ (_MML_). Note, if a strong end-to-end encryption alongside an authentication of the endpoint would additionally be facilitated, this would prevent a man-in-the-middle attack (see also above for MME). However, filtering cannot fully protect against MML. _RCE:_  
Although there is no direct influence on _RCE_ vulnerability, _Bark_ can still prevent the attack if the corresponding communication is not whitelisted, as previously discussed. If a device is protected, it depends on whether or not the attacking device needs access to the service that also provides the vulnerabilities. As some attacks are prevented while others are not, a _medium_ influence rating is assigned here (_RCE_). _SMU:_  
It is clear that there is _no or only low_ influence on the usage of insufficient authentication mechanisms by the server (_SMU_). _SSC:_  
In the event that an external attacker does not spoof the IP address, their address will not be whitelisted. Nevertheless, this scenario is only applicable if the device is accessible via an open port on the router. In the case where the attacker also spoofs the server's address, the influence is assumed to be _no or only low_ according to the discussion on the _INE_ vector. If the attacker originates from within the network, the success of the attack is dependent on the communication that has been whitelisted. Overall, a rating of _some_ influence is assigned in this instance (_SSC_). _WDA:_  
Because a WLAN deauthentication attack is performed from outside the local network, _no or only low_ influence of a filtering approach is assumed here (_WDA_). _XNE:_  
All sub-vectors of this vector have been assessed as _no or only low_, which consequently is also the rating for this one (_XNE_). _XNL:_  
All sub-vectors of this vector have been assessed as _medium_, which consequently is also the rating for this one (_XNL_). Scenario-Specific Adjustments  
_S\({}_{\alpha}\) (Communication with the Internet):_  
By definition, communication with the _Unessential Server_ is not necessary (see Section 5), and it would therefore not be whitelisted in _Bark_. Because communication with the _Unessential Server_ is inhibited, it is assumed that the server stores no or at least fewer data of a device. Hence, the influence on the \(DBO\) vector is rated as _medium_ for the _Unessential Server_. Additionally, because there is no communication from the _Smart Home Device_ to this server, it cannot be eavesdropped on, leading to a _high_ influence on the corresponding _ENE_ vector (This would also apply to some of the other network traffic vectors, which, however, do not appear in a relevant entry).