Commit 44fecbb2 authored by Valerie Aurora's avatar Valerie Aurora
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Update Clause 5.11/6.11 Non-interference to revised structure (was 5.2.4)

closes #159
parent fa781a60
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@@ -1028,37 +1028,6 @@ The product shall minimize the data processing by the product.

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### 5.2.4 ER-MINI: Minimize impact on other devices and services

#### 5.2.4.1 Cybersecurity requirement

The product shall implement appropriate mitigations to minimize impact on other devices and services.

#### 5.2.4.2 MI-MDOC: Document transfer of risk of minimizing impact to operating environment

The product shall be accompanied by documentation informing the user of the transfer of risk for minimizing impact on other devices and services.

  * Reference: ER-MINI
  * Objective: Minimize impact on other devices and services
  * Activities: Examine the documentation
  * Verdict: Transfer of risk documented in a manner appropriate to the user => PASS, otherwise FAIL
  * Evidence: Documentation, analysis of documentation

#### 5.2.4.3 MI-MPHY: Prevent denial of service at physical layer

The product shall implement methods of detecting and mitigating denial of service attacks on other devices resulting from exploitation of vulnerabilities on the product via network or host system access.

  * Reference: ER-MINI
  * Objective: Minimize impact on other devices and services
  * Preparation: List known attack methods that generate output on the transmission medium originating in the product itself that negatively impact other devices and services
  * Activities: Use a tool to simulate these attacks and observe whether the product notifies the host or mitigates the negative impact itself
  * Verdict: Product notifies host or mitigates the negative impact itself  => PASS, otherwise FAIL
  * Evidence: List of attack methods, list of negative behaviours tested, log messages of product behaviour, log on host system

#### 5.2.5.8 Mapping of mitigations to risk factors and security profiles

See clause 5.3 for which mitigations are necessary for which security profiles and Annex C.4 for the rationale.

## 5.10 Availability protection

### 5.10.1 Overview
@@ -1119,6 +1088,28 @@ The product shall implement a mechanism to trigger an automatic reset when it de

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## 5.11 Non-interference

### 5.11.1 Overview

This clause addresses the requirements in the CRA [\[i.1\]](#_ref_i.1) Annex 1 Part 1 (2) (i).

### 5.11.2 REQ-NI-01: Minimise data transmitted to unverified sources

#### 5.11.2.1 Requirement

The product shall minimise the data originating from the product itself that is transmitted to a destination that has not been verified as requesting the transmitting data.

#### 5.11.2.2 Applicability

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#### 5.11.2.3 Guidance

Denial of service attacks over the network often use traffic reflection or amplification techniques, in which the threat actor sends packet to third party devices with a spoofed source address. The third party then sends a response packet to the spoofed source destination - a reflection attack. If the response is larger than the packet it is responding to, then it is an amplification attack. By minimising or rate-limiting the data sent to potentially spoofed source addresses, a product can reduce its interference with other devices.

This requirement operates at the link layer (IP) or data link layer and/or physical layer (OSI model). Interfaces of this type are relatively uncommon for the products in the scope of the present document and are mostly located outside the product, in higher layers of the network stack. Non-interference at higher layers in the network stack is the responsibility of the operational environment.

### 5.2.14 ER-LMAS: Minimize exposed interfaces

#### 5.2.14.1 Cybersecurity requirement
@@ -2199,6 +2190,41 @@ Otherwise FAIL
* Log of device activity and/or state
* Packet captures

## 6.11 Non-interference

### 6.11.1 Overview

This clause addresses the requirements in the CRA [\[i.1\]](#_ref_i.1) Annex 1 Part 1 (2) (i).

### 6.11.2 REQ-NI-01: Minimise data transmitted to unverified sources

#### 6.11.2.1 Objective

Minimise negative impact on other devices or services.

#### 6.11.2.2 Preparation

Identify interfaces that may transmit data originating from the product itself in reply to incoming data to addresses that have not been verified as requesting the transmitted data. Identify network input that may cause the interface to transmit data in such a manner.

#### 6.11.2.3 Activities

For each identified network input, transmit the input to the interface and record any data the product transmits in response. Analyse the amount of data sent in response in the context of the product function and cybersecurity risk assessment.

#### 6.11.2.4 Verdict

PASS if the response is consistent with reasonable minimisation of data in the response.

Otherwise FAIL

#### 6.11.2.5 Evidence

* List of identified interfaces
* List of methods for identifying interfaces
* Sufficiency analaysis of methods for identifying interfaces
* List of identified inputs
* Packet captures or other appropriate logs of the data transmitted
* Sufficiency analysis of analysis of amount of data in response

# Annex A (informative): Relationship between the present document and the CRA

<mark>Editor's Note: Even if informative, this Annex is mandatory in Harmonised Standards.</mark>