5 ms·

Why do you call it a deliberate backdoor when the Apple developers (see elsewhere in this thread) have said this was a bug?

kristofferR 6y ago
You don't create a whitelist system literally called ContentFilterExclusionList by accident.
- zaphirplane 6y ago
  A backdoor has some malicious connotations to me. Having security profiles controlled by a list seems a thing Without spending a lot of time sshd has allowLists (AllowGroups) and match directives Sudo also has per group config As a user on any operating system what you can and can’t do is controlled by a list Perhaps the issue is the list isn’t user controlled ? Perhaps the issue falls into the “I own and control my device” vs “we sell you a safe, foot gun safe, easy to use device (in their opinion)”
  - jakubp 6y ago
    If they claim "here's the API you can use to control network access" but can then put arbitrary apps to work around that, that's the definition of backdoor access to the device.
    - zaphirplane 6y ago
      I’m not supporting their approach. Why can’t this be thought of as a control API with a built in allow list ? Where the list is hidden by obscurity
  - yarcob 6y ago
    A "back door" is any kind of mechanism that was added by the vendor to circumvent security mechanisms. Back doors are typically not disclosed to the user, and can't be turned off. So for example an automatic software update mechanism isn't a back door, as the user is aware of it and can typically turn it off if they are concerned about security. An undisclosed mechanism that allows Apple apps to circumvent firewalls does very much fit the description of a back door. Intent doesn't matter with regards to back doors. Most back doors are not made with malicious intent, or at least the vendors usually claim that they only had good intentions for the back door. (Eg. see the recent reports where a router manufacturer had a secret password that they claimed was only used for software updates) The danger about back doors is that malicious software can use the back doors to circumvent the security measures, just like Patrick Wardle demonstrated that it was possible to use Apple's content filter exclusion to circumvent firewalls.
felipelemos 6y ago
How a 'ContentFilterExclusionList' creation can be a bug? Somebody hit the wrong keys by mistake and nobody noticed during the pull request review?
- jansan 6y ago
  Entirely possible if an infinite number of monkeys type along on an infinite number of keyboards. https://en.wikipedia.org/wiki/Infinite_monkey_theorem https://en.wikipedia.org/wiki/Infinite_monkey_theorem
  - _underfl0w_ 6y ago
    Incidentally, probably an apt depiction of Apple's development process :P
Lammy 6y ago
"Hanlon's razor" is a gift to the malicious. I've stopped believing in it entirely.
- stretchcat 6y ago
  Agreed. Nearly every kid discovers the 'it was an accident' lie/excuse. And I don't think adults ever forget it.
webmobdev 6y ago
(That tweet has been deleted by the Apple developer). Before macOS Big Sur / Catalina, many of these application firewalls - Lulu, Little Snitch, HandsOff, TripMode, RadioSilence etc. - all used their own kernel extensions to effectively monitor and block any processes from connecting to the internet. Firewalls are system security softwares. And naturally Apple would prefer to oversee and have this in-built in their OS. Apple also wants to discourage kernel extensions on macOS (they have some good reasons - a poorly designed kernel extension can make the OS unstable; but mostly its about feature control with Apple). So they informed all such firewall app developers that their individual kernel extensions will no longer be allowed, and Apple had instead created an OS API specifically for their use case. (They described the features it would have and invited them to give their feedback). And so all application firewalls were forced to update their apps and use this OS API. But this API had an undisclosed, in-built list of Apple approved applications that no firewall was allowed to block. Someone created that list. Someone added that list in the system, and coded the API to specifically give them special privileges to bypass any application firewalls. Bugs are accidental. Backdoors like these are intentional. (You can however take exception to the usage of "Backdoor" here - perhaps from Apple's perspective it was a good design decision as many of these services go wacko, and sometimes even freeze your system, when they aren't allowed to do what they are coded to, like do some operation over the internet. I've often seen CPU spikes and slowdowns when you block some of these services.)
- raverbashing 6y ago
  I agree, this is 90% likely malicious. The non-malicious usage I can imagine is that for debugging the firewall you don't want to lock your other services out of it in case something goes wrong (or as you said, for reliability issues)
  - webmobdev 6y ago
    My fear is that Apple will now make the design decision to make these services more unreliable if blocked. Like I experienced, others too have noticed similar behaviour: > It’s worth noting that Big Sur and its predecessors are built to assume that they can talk to Apple at any time, but when we don’t allow it, a few unwanted side effects pop up. For example, the keyboard sometimes takes longer to wake up from sleep mode. Or, in certain situations, the Mullvad app takes longer to detect that the computer is online. - https://mullvad.net/en/blog/2020/11/16/big-no-big-sur-mullvad-disallows-apple-apps-bypass-firewall/ https://mullvad.net/en/blog/2020/11/16/big-no-big-sur-mullva... (Ofcourse, as a developer, I can sympathize with the Apple developers - when you design a product to use the internet, you don't really think hard about all kinds of use cases where internet access is deliberately denied).
pstrateman 6y ago
> Why do you call it a deliberate backdoor when the Apple developers (see elsewhere in this thread) have said this was a bug? They're lying.
- novaRom 6y ago
  Every year the same actually.
- kalleboo 6y ago
  Why would they lie and not just shut the hell up? It makes no sense.
  - webmobdev 6y ago
    Sometimes people talk, even when they should shut the hell up. (The Apple developer has since deleted his tweet).
    - kalleboo 6y ago
      He deleted his tweet because everyone was piling on him with nasty replies
rorykoehler 6y ago
It's always a bug. Fool me once....
jarym 6y ago
Perhaps they meant it was a bug in management because the code was very much intentional
xxs 6y ago
> have said this was a bug They can say whatever they like, it's another story they've got no credibility. It was quite obvious it was very much a deliberate action (just look at the naming, itself)

kristofferR 6y ago

You don't create a whitelist system literally called ContentFilterExclusionList by accident.

zaphirplane 6y ago
A backdoor has some malicious connotations to me. Having security profiles controlled by a list seems a thing Without spending a lot of time sshd has allowLists (AllowGroups) and match directives Sudo also has per group config As a user on any operating system what you can and can’t do is controlled by a list Perhaps the issue is the list isn’t user controlled ? Perhaps the issue falls into the “I own and control my device” vs “we sell you a safe, foot gun safe, easy to use device (in their opinion)”
- jakubp 6y ago
  If they claim "here's the API you can use to control network access" but can then put arbitrary apps to work around that, that's the definition of backdoor access to the device.
  - zaphirplane 6y ago
    I’m not supporting their approach. Why can’t this be thought of as a control API with a built in allow list ? Where the list is hidden by obscurity
- yarcob 6y ago
  A "back door" is any kind of mechanism that was added by the vendor to circumvent security mechanisms. Back doors are typically not disclosed to the user, and can't be turned off. So for example an automatic software update mechanism isn't a back door, as the user is aware of it and can typically turn it off if they are concerned about security. An undisclosed mechanism that allows Apple apps to circumvent firewalls does very much fit the description of a back door. Intent doesn't matter with regards to back doors. Most back doors are not made with malicious intent, or at least the vendors usually claim that they only had good intentions for the back door. (Eg. see the recent reports where a router manufacturer had a secret password that they claimed was only used for software updates) The danger about back doors is that malicious software can use the back doors to circumvent the security measures, just like Patrick Wardle demonstrated that it was possible to use Apple's content filter exclusion to circumvent firewalls.

felipelemos 6y ago

How a 'ContentFilterExclusionList' creation can be a bug? Somebody hit the wrong keys by mistake and nobody noticed during the pull request review?

jansan 6y ago
Entirely possible if an infinite number of monkeys type along on an infinite number of keyboards. https://en.wikipedia.org/wiki/Infinite_monkey_theorem https://en.wikipedia.org/wiki/Infinite_monkey_theorem
- _underfl0w_ 6y ago
  Incidentally, probably an apt depiction of Apple's development process :P

Lammy 6y ago

"Hanlon's razor" is a gift to the malicious. I've stopped believing in it entirely.

stretchcat 6y ago
Agreed. Nearly every kid discovers the 'it was an accident' lie/excuse. And I don't think adults ever forget it.

webmobdev 6y ago

(That tweet has been deleted by the Apple developer). Before macOS Big Sur / Catalina, many of these application firewalls - Lulu, Little Snitch, HandsOff, TripMode, RadioSilence etc. - all used their own kernel extensions to effectively monitor and block any processes from connecting to the internet. Firewalls are system security softwares. And naturally Apple would prefer to oversee and have this in-built in their OS. Apple also wants to discourage kernel extensions on macOS (they have some good reasons - a poorly designed kernel extension can make the OS unstable; but mostly its about feature control with Apple). So they informed all such firewall app developers that their individual kernel extensions will no longer be allowed, and Apple had instead created an OS API specifically for their use case. (They described the features it would have and invited them to give their feedback). And so all application firewalls were forced to update their apps and use this OS API. But this API had an undisclosed, in-built list of Apple approved applications that no firewall was allowed to block. Someone created that list. Someone added that list in the system, and coded the API to specifically give them special privileges to bypass any application firewalls. Bugs are accidental. Backdoors like these are intentional. (You can however take exception to the usage of "Backdoor" here - perhaps from Apple's perspective it was a good design decision as many of these services go wacko, and sometimes even freeze your system, when they aren't allowed to do what they are coded to, like do some operation over the internet. I've often seen CPU spikes and slowdowns when you block some of these services.)

raverbashing 6y ago
I agree, this is 90% likely malicious. The non-malicious usage I can imagine is that for debugging the firewall you don't want to lock your other services out of it in case something goes wrong (or as you said, for reliability issues)
- webmobdev 6y ago
  My fear is that Apple will now make the design decision to make these services more unreliable if blocked. Like I experienced, others too have noticed similar behaviour: > It’s worth noting that Big Sur and its predecessors are built to assume that they can talk to Apple at any time, but when we don’t allow it, a few unwanted side effects pop up. For example, the keyboard sometimes takes longer to wake up from sleep mode. Or, in certain situations, the Mullvad app takes longer to detect that the computer is online. - https://mullvad.net/en/blog/2020/11/16/big-no-big-sur-mullvad-disallows-apple-apps-bypass-firewall/ https://mullvad.net/en/blog/2020/11/16/big-no-big-sur-mullva... (Ofcourse, as a developer, I can sympathize with the Apple developers - when you design a product to use the internet, you don't really think hard about all kinds of use cases where internet access is deliberately denied).

pstrateman 6y ago

> Why do you call it a deliberate backdoor when the Apple developers (see elsewhere in this thread) have said this was a bug? They're lying.

novaRom 6y ago
Every year the same actually.
kalleboo 6y ago
Why would they lie and not just shut the hell up? It makes no sense.
- webmobdev 6y ago
  Sometimes people talk, even when they should shut the hell up. (The Apple developer has since deleted his tweet).
  - kalleboo 6y ago
    He deleted his tweet because everyone was piling on him with nasty replies

rorykoehler 6y ago

It's always a bug. Fool me once....

jarym 6y ago

Perhaps they meant it was a bug in management because the code was very much intentional

xxs 6y ago

> have said this was a bug They can say whatever they like, it's another story they've got no credibility. It was quite obvious it was very much a deliberate action (just look at the naming, itself)