4 ms·

Yeah, except one side is obviously correct. Not knowing what program will open up when they click a file is insane.

__MatrixMan__ 3y ago
Having files double as a launcher for some program was a mistake, the result of which is that we not how have to sit through those awful trainings about not clicking untrusted files. Just open the program first. People should fear untrusted programs, but should be at ease viewing data through programs that they trust.
- gmac 3y ago
  (1) I would find this very annoying. (2) I suspect for lots of files, lots of users wouldn't know which program to open.
  - __MatrixMan__ 3y ago
    I guess I'm not in a good position to judge how annoying it would be for others. I can't remember the last time I let the OS decide how to handle a file type. As for (2)... good. Asking your computer to perform actions that you understand so poorly that you can't figure out what program is going to run is a recipe for disaster. That's the behavior we should be training people to avoid, not merely engaging with suspicious data but doing so recklessly.
    - mminer237 3y ago
      I understand computers plenty well, but I can't envision any scenario where not knowing the default program for a file type would bring disaster. No one should have to memorize what program opens every file, and there's no good way to even learn that information easily. I want to open a photo. Why would I care whether this system uses Shotwell or GNOME Photos or what have you? How would I even learn what's possible? Especially with Linux, there's so much fragmentation that just trying to open the file manager feels like a guessing game of going through all the ones I've heard of to see which works until I finally break down and Google what fork this distro uses. That change would make computers completely unusable beyond Chrome and maybe Office for 99% of people.
      - alexvitkov 3y ago
        You certainly will care if you double click a .png and suddenly WinRAR opens up, because that .png is actually an ACE archive (application/x-ace-compressed), and guess what ACE stands for - arbitrary code execution! Probably not, but they've had one for 20-ish years: [1] I find that insane, and that's basically what happens on Linux today. [1] https://www.theverge.com/2019/2/21/18234448/winrar-winace-19-year-old-vulnerability-patched-version-5-70-beta-1 https://www.theverge.com/2019/2/21/18234448/winrar-winace-19...
        __MatrixMan__ 3y ago
        What happened to me today on Linux was `$ geeqie image.png`. It might be possible to trick geeqie into doing something bad, but it's a heck of a lot harder.
        mminer237 3y ago
        If it's a .png, it would open up in Microsoft Photos/eog/LXImage for me. Obviously some exploit could be found in there and any untrusted file is a risk, but it won't open WinRAR. That's the whole point of why file extensions are so much better than any alternative.
      - __MatrixMan__ 3y ago
        I'm not the pen tester, I just hang out with him, but the particular disaster I'm thinking of has to do with samba file shares. I guess there's some file extension that will prompt windows to attempt to log in to the server at an address found in the file. So you email that file to your target and when they open it it sends you their password under the auspices that you're an internal samba file share. As I understand it, a very large portion of the attacker's toolkit has to do with tricking users into running programs they've never heard of by clicking things they think are familiar. But the real disaster is not the successful attacks, it's the culture that we're creating where users are taught to click things and trust the OS default behavior while simultaneously trained to never click things that seem out of the ordinary. It creates a paralysis in the user when it comes to exploring their tooling and fails to create a learning gradient. This widens the gap between them and people like you and me. That's a disaster for them because they get taken advantage of by people in the know, and it's a disaster for you and me because they end up blindly supporting bad behavior (drm, companies mishandling user data, etc) since it's bad in a dimension that they've been locked out of by our failure to pave a path towards competence.
- alexvitkov 3y ago
  All programs become untrusted after they reach a certain size. It's highly unlikely that a 1,000,000 line monstrosity with a file format so complex no single human can understand has no exploitable flaws in its file handling. With "open by extension" the .pdf file can only target vulnerabilities in my PDF reader, but with "open by mimetype" they could be trying to exploit any program that is configured to open files. If you're doing "open by extension" and know that Adobe's exquisite PDF reader will open when you double click a PDF, doing so is not more unsafe than opening up Reader and navigating to the file from within. That's without mentioning the main obvious advantage of "open by extension" - the fact that I can configure programs that open file formats that haven't been blessed by whoever wrote your `file` utility.
- pbhjpbhj 3y ago
  IIRC my KDE has little icon overlays, so a traffic cone on the mp4 preview image or mp4 icon. That seems like a nice way to give that information. But, it's using magic numbers.
michaelcampbell 3y ago
You don't REALLY know NOW. You rely on the assumption that the extension->application maps in a given machine are sane.
- alexvitkov 3y ago
  A string->string table is not that difficult to get right, I've never been surprised by what happens when I open a file in Windows. I could write 10 paragraphs on the thought process which my Linux install goes through as it decides that when I click a .zip file the correct behavior is to open it in Chromium and immediately download it to ~/Downloads.
  - mauvia 3y ago
    I've had this exact kind of problem where windows decides to open picture files in edge because the image preview program doesn't understand it.
  - michaelcampbell 3y ago
    > A string->string table is not that difficult to get right You're correct, which makes it doubly confusing as to why Windows doesn't do it.

Having files double as a launcher for some program was a mistake, the result of which is that we not how have to sit through those awful trainings about not clicking untrusted files. Just open the program first. People should fear untrusted programs, but should be at ease viewing data through programs that they trust.

gmac 3y ago
(1) I would find this very annoying. (2) I suspect for lots of files, lots of users wouldn't know which program to open.
- __MatrixMan__ 3y ago
  I guess I'm not in a good position to judge how annoying it would be for others. I can't remember the last time I let the OS decide how to handle a file type. As for (2)... good. Asking your computer to perform actions that you understand so poorly that you can't figure out what program is going to run is a recipe for disaster. That's the behavior we should be training people to avoid, not merely engaging with suspicious data but doing so recklessly.
  - mminer237 3y ago
    I understand computers plenty well, but I can't envision any scenario where not knowing the default program for a file type would bring disaster. No one should have to memorize what program opens every file, and there's no good way to even learn that information easily. I want to open a photo. Why would I care whether this system uses Shotwell or GNOME Photos or what have you? How would I even learn what's possible? Especially with Linux, there's so much fragmentation that just trying to open the file manager feels like a guessing game of going through all the ones I've heard of to see which works until I finally break down and Google what fork this distro uses. That change would make computers completely unusable beyond Chrome and maybe Office for 99% of people.
    - alexvitkov 3y ago
      You certainly will care if you double click a .png and suddenly WinRAR opens up, because that .png is actually an ACE archive (application/x-ace-compressed), and guess what ACE stands for - arbitrary code execution! Probably not, but they've had one for 20-ish years: [1] I find that insane, and that's basically what happens on Linux today. [1] https://www.theverge.com/2019/2/21/18234448/winrar-winace-19-year-old-vulnerability-patched-version-5-70-beta-1 https://www.theverge.com/2019/2/21/18234448/winrar-winace-19...
      - __MatrixMan__ 3y ago
        What happened to me today on Linux was `$ geeqie image.png`. It might be possible to trick geeqie into doing something bad, but it's a heck of a lot harder.
      - mminer237 3y ago
        If it's a .png, it would open up in Microsoft Photos/eog/LXImage for me. Obviously some exploit could be found in there and any untrusted file is a risk, but it won't open WinRAR. That's the whole point of why file extensions are so much better than any alternative.
    - __MatrixMan__ 3y ago
      I'm not the pen tester, I just hang out with him, but the particular disaster I'm thinking of has to do with samba file shares. I guess there's some file extension that will prompt windows to attempt to log in to the server at an address found in the file. So you email that file to your target and when they open it it sends you their password under the auspices that you're an internal samba file share. As I understand it, a very large portion of the attacker's toolkit has to do with tricking users into running programs they've never heard of by clicking things they think are familiar. But the real disaster is not the successful attacks, it's the culture that we're creating where users are taught to click things and trust the OS default behavior while simultaneously trained to never click things that seem out of the ordinary. It creates a paralysis in the user when it comes to exploring their tooling and fails to create a learning gradient. This widens the gap between them and people like you and me. That's a disaster for them because they get taken advantage of by people in the know, and it's a disaster for you and me because they end up blindly supporting bad behavior (drm, companies mishandling user data, etc) since it's bad in a dimension that they've been locked out of by our failure to pave a path towards competence.
alexvitkov 3y ago
All programs become untrusted after they reach a certain size. It's highly unlikely that a 1,000,000 line monstrosity with a file format so complex no single human can understand has no exploitable flaws in its file handling. With "open by extension" the .pdf file can only target vulnerabilities in my PDF reader, but with "open by mimetype" they could be trying to exploit any program that is configured to open files. If you're doing "open by extension" and know that Adobe's exquisite PDF reader will open when you double click a PDF, doing so is not more unsafe than opening up Reader and navigating to the file from within. That's without mentioning the main obvious advantage of "open by extension" - the fact that I can configure programs that open file formats that haven't been blessed by whoever wrote your `file` utility.
pbhjpbhj 3y ago
IIRC my KDE has little icon overlays, so a traffic cone on the mp4 preview image or mp4 icon. That seems like a nice way to give that information. But, it's using magic numbers.

michaelcampbell 3y ago

You don't REALLY know NOW. You rely on the assumption that the extension->application maps in a given machine are sane.

alexvitkov 3y ago
A string->string table is not that difficult to get right, I've never been surprised by what happens when I open a file in Windows. I could write 10 paragraphs on the thought process which my Linux install goes through as it decides that when I click a .zip file the correct behavior is to open it in Chromium and immediately download it to ~/Downloads.
- mauvia 3y ago
  I've had this exact kind of problem where windows decides to open picture files in edge because the image preview program doesn't understand it.
- michaelcampbell 3y ago
  > A string->string table is not that difficult to get right You're correct, which makes it doubly confusing as to why Windows doesn't do it.