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The client visits http://example.com/ and they had not visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ and they had not visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ and they had visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

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Lets look at some scenarios. In all scenarios I will assume that example.com is not in any browser prelod lists. I will also assume that http://example.com redirect to https://example.com

The client visits http://example.com/ whichand they had not visited example.com before the MITM esablished themselves.

The client visits http://example.com/ whichand they had visited example.com before the MITM esablished themselves. The attacker does not posses a certificate that will pass the browsers normal certificate validation.

The client visits https://example.com/ whichand they havehad not visited example.com before thethe MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list (by trickery, bribery, bullying or whatever)

The client visits https://example.com/ whichand they have nothad visited example.com before thethe MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ whichand they had not visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

Lets look at some scenarios. In all scenarios I will assume that example.com is not in any browser prelod lists

The client visits http://example.com/ which they had not visited before the MITM esablished themselves.

The client visits http://example.com/ which they had visited before the MITM esablished themselves. The attacker does not posses a certificate that will pass the browsers normal certificate validation.

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list (by trickery, bribery, bullying or whatever)

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ which they had visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

Lets look at some scenarios. In all scenarios I will assume that example.com is not in any browser prelod lists. I will also assume that http://example.com redirect to https://example.com

The client visits http://example.com/ and they had not visited example.com before the MITM esablished themselves.

The client visits http://example.com/ and they had visited example.com before the MITM esablished themselves. The attacker does not posses a certificate that will pass the browsers normal certificate validation.

The client visits https://example.com/ and they had not visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list (by trickery, bribery, bullying or whatever)

The client visits https://example.com/ and they had visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ and they had not visited example.com before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

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True or False: HSTS is absolutely useless against MITM attacks False, HSTS protects against certain categories of MITM attack but not against others.

False, HSTS protects against certain categories of MITM attack but not against others.

HKP (I know you didn't ask about this but I feel it doesn't make sense to look at one without looking at the other) also protects against certain categories of MITM attacks but not against others.

The combination of HSTS and HKP protects against certain attacksan attack scenario that neither alone can protect against.

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list (by trickery, bribery, bullying or whatever) that will pass normal validation for example.com

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA that will pass normal validation for examplein the browsers default trusted roots list.com

The client visits http://example.com/ which they had visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA that will pass normal validation for examplein the browsers default trusted roots list.com

The MITM will succeed

Scenario 8:

The MITM has obtained a certficate for exampe.com from a CA that was manually added to the trusted roots list.

HKP is bypassed and the MITM will succed. (this allows corporate firewalls that inspect https to continue to work, whether that is a good thing or not is debatable).

True or False: HSTS is absolutely useless against MITM attacks False, HSTS protects against certain categories of MITM attack but not against others.

HKP also protects against certain categories of MITM attacks but not against others.

The combination of HSTS and HKP protects against certain attacks that neither alone can protect against.

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate from a CA (by trickery, bribery, bullying or whatever) that will pass normal validation for example.com

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate from a CA that will pass normal validation for example.com

The client visits http://example.com/ which they had visited before the MITM esablished themselves. The attacker has obtained a certificate from a CA that will pass normal validation for example.com

The MITM will succeed

True or False: HSTS is absolutely useless against MITM attacks

False, HSTS protects against certain categories of MITM attack but not against others.

HKP (I know you didn't ask about this but I feel it doesn't make sense to look at one without looking at the other) also protects against certain categories of MITM attacks but not against others.

The combination of HSTS and HKP protects against an attack scenario that neither alone can protect against.

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list (by trickery, bribery, bullying or whatever)

The client visits https://example.com/ which they have not visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The client visits http://example.com/ which they had visited before the MITM esablished themselves. The attacker has obtained a certificate coverting example.com from a CA in the browsers default trusted roots list.

The MITM will succeed

Scenario 8:

The MITM has obtained a certficate for exampe.com from a CA that was manually added to the trusted roots list.

HKP is bypassed and the MITM will succed. (this allows corporate firewalls that inspect https to continue to work, whether that is a good thing or not is debatable).

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