Warning: HFS v2.x has a severe vulnerability

[LeoNeeson]

@Alps: Using "deactivate Browsable" doesn't make any difference here (you can use it, but it doesn't stop this vulnerability). The only setting that stops it, is disabling macros (since the problem is there). With macros disabled, even search works fine, you only need to use a simple template that doesn't need or use macros.

I correct myself (my mistake): @Alps was right on his first message (and then here), by unchecking the 'Browsable' flag on the 'Home/Root' of HFS, you could avoid this vulnerability and be safe. That seems to be enough, but if you also disable macros, you are twice protected. If you use v2.4 and need to use the login system, then don't disable macros (using v2.3 you can disable macros + uncheck browsable flag, since login system depends on the browser).


Summarizing, now we have 2 options to be safe and avoid this vulnerability:

- Option A: unchecking the 'Browsable' flag
1) Inside HFS, make sure 'You are in Expert mode' (if not switch by pressing F5)
2) In 'Virtual File System' panel, right-click on the 'Home' icon, select 'Properties...'
3) Properties window will open, go to 'Flags' tab, and uncheck 'Browsable' option.
4) Click 'OK' to apply changes, and from now on, any visitor to your HFS server, will see this message: "Forbidden / This resource is not accessible", and you will not have file listing, neither file search.

- Option B: disabling the 'macros' feature
Simply follow the steps described in this post, here.

I give all the credits for both of these methods to @Alps!

Cheers,
Leo.-

[Alps]

Not only my credits.
Was only a idea from me.
I not have the knowledge for security relevance.
Without LeoNeeson we not have this solution.

[Mars]

Since there are still a fans of hfs 2.3m build 300, and who are concerned about the risk of being hackered with the EXEC macro, the simplest at the moment is to allow a deactivation of this macro which is only rarely used and in very specific cases,

the solution envisaged to limit the number of accessible external programs that would be included in a reduced list is not possible at the moment as long as an effective filtering is not possible for the moment to be possible.


This is an ephemeral link on a version  compressed with upx, wich has not be endorsed by rejetto, but because of my previous participation in the project I can afford it without waiting
 it integrates a button in the toolbar to activate the use of the macro exec.
HFS 2.3m build 305

the macro is systematically in OFF mode as soon as the server is started up or at each change of state of the latter.

the macro is automatically deactivated when the display is switched to EASY mode, and the button is inoperative.

when the conditions are met, it is possible to activate the use of the EXEC macro for a period of 30 seconds, this value can be modified by right-clicking on the button,

any change to a value other than that displayed on the opening of the message causes the timer to stop, so it is necessary to reactivate the button.

As a measure of simplicity, a zero value inhibits the timer and the button becomes a simple state flip-flop, otherwise it behaves like a timer.

[LeoNeeson]

Good! ...and now we have:

- Option C: Mars’s version of HFS! (v2.3m Build 305)
This option is perfect for those who want to make normal use of the default template (while also wanting to programmatically run programs using HFS, but don’t want to leave this option enabled for too long). This also provides another alternative (besides 'Option A or B') for those who wish to disable the 'exec' macro feature to be more secure.

What is the difference between 'Option B' and 'Option C'? The difference is that 'Option B' disables all macros (including the less risky macros that are necessary for normal template functionality), while the Mars compilation only disables the 'exec' macro (which allows other programs to be executed, and this was exploited by this vulnerability). Since the vulnerability still exists, if you use 'Option C' (and enable the 'exec' macro), it's best to allow it only for a short period, or to disable it directly when this feature is not needed.

It’s nice to have more options for those who may need them.
Everything seems fine, and it’s good, coming from Mars (congrats!)

[Rapid]

Hi Leo!
Could you check my versions, if it vulnerable or not? As I'm not really understand your answers per my fixes.
In my tests, I couldn't repeat vulnerability examples. May be I checked not enough?

My latest version: https://rnq.ru/downloads/download/8-hfs/215-hfs-324-x64

[Mars]

@Rapid

With a download size of 0 bits, your HFS breaks all compression records 

[LeoNeeson]

Since we are joking...

@Rapid: You did it! 0 bits = 0 vulnerabilities !

@Mars: Now I do understand why your timer is set to 30 seconds...
...and also because it only takes '30 seconds to Mars'
...a nice rock band, although I prefer Bruno Mars

I'm sorry, I think I went too far today...
(too many jokes in one post)

[Rapid]

ok, download link is fixed.

I really don't understand, why you afraid only 'exec' macros. With "save" macros it's possible to do the same (if write 'bat' or 'lnk' file). With 'add folder' - it's possible to add home folder of active user, and maybe download something private.

[Mars]

In the face of all these hacking possibilities, it is up to the fact that hfs is running on a virtual machine in a restricted environment.

HFS is of an old design, no matter how much we try to plug the holes, but we'll never be safe from further leaks.
it is always possible to use version 2.2f which makes it possible to distribute content as one looks at a film,

otherwise we use a version with macros, which allows a certain interactivity, but it's like with games, there's always some that will always try to cheat to win not much except forge in the idea that they beat the designer in his efforts to make his product inviolable. It's a racing game where we can quickly make mistakes that make us lose the race.

the race here is that of inventiveness that will give the one who will be the most clever to supplant the other by cutting off the grass under his foot, like a chess player it is not because we lose coins or even the queen that we are on the ground as long as failure and matte is not announced

[LeoNeeson]

Could you check my versions, if it vulnerable or not? As I'm not really understand your answers per my fixes.

I've sent you a private message because I can't run x64 apps.
You can use 1Fichier to upload files if that's easier for you.
Until then, I can't review your version; I'm sorry...

I really don't understand, why you afraid only 'exec' macros. With "save" macros it's possible to do the same (if write 'bat' or 'lnk' file). With 'add folder' - it's possible to add home folder of active user, and maybe download something private.

I completely agree with you (and I was already aware of all that).

it is always possible to use version 2.2f which makes it possible to distribute content as one looks at a film,

We can have the best of both worlds if we do this:

(Ideas) The best way to achieve good security would be:
• Make the default template not use or require any macros at all.
• Make the entire macro system behave exactly like user permissions.
• Have a config panel to let HFS admin choose which macros are enabled.
Even then, nobody could guarantee 100% permanent security forever...

Making all those changes will take a lot of work, time, and testing.
(but it will provide all the features without compromising security)

[Rapid]

I've sent you a private message because I can't run x64 apps.
...

32bit: https://rnq.ru/categories/download/8-hfs/216-hfs-324

...
We can have the best of both worlds if we do this:

(Ideas) The best way to achieve good security would be:
• Make the default template not use or require any macros at all.
• Make the entire macro system behave exactly like user permissions.
• Have a config panel to let HFS admin choose which macros are enabled.
Even then, nobody could guarantee 100% permanent security forever...

Making all those changes will take a lot of work, time, and testing.
(but it will provide all the features without compromising security)

I think you misunderstands what macroses are. Templates are based on macroses. So "no macros" = "no templates".
For me HFS is just a Home File Server. I don't really care about security.
All changes are just for fun...
Like a beautiful alpha-blend icons, serving thumbnails as WEBP,  using ZSTD compression instead of zlib. Nobody needs it, but it's fun to do
So the next big fun is to add "zip format for folder archives"

[Mars]

what is missing it´s a swtich of templates as exist when we use a computer or smartphones for example, but in this case it´s more simple to have two versions of hfs and run only the one with macros or not

[LeoNeeson]

I think you misunderstands what macroses are.
Templates are based on macroses.
So "no macros" = "no templates".

By saying 'templates are based' on macros, it could only mean 'some templates depend' on macros (but only those templates that need a macro to work, like, for example, the default template). However, your latest statement is not entirely accurate, since you can have a template without macros. Otherwise, you would not be able to install or use the templates I've modified in this post HERE, which can be used with macros disabled (obviously, some features are disabled, such as the ability to delete, rename, or upload files, but it's still a template after all). I'm not looking to argue, but I do have a clear understanding of what macros are and how they work.

For me HFS is just a Home File Server.
I don't really care about security.
All changes are just for fun...

Then, just for fun, you have given me the opportunity to say the following: "Ladies and gentlemen, we now have..."

- Option D: DRapid version of HFS! (32 bits & 64 bits)
Yeah! this version is good for those who want to use templates while avoiding this vulnerability, and also for those who, based on his own words (not mine): 'don't really care about security'. So, if you feel comfortable with this, you will find this version very interesting.

» Seriously speaking, from what I've seen by running the program and conducting some tests (and also after reviewing the patch in the source code from an older build), it seems to avoid the vulnerability. However, I don't see this as a definitive long-term solution. That being said, I can't provide ANY guarantees, and it's up to the end-user to decide whether this is appropriate to use or not.

what is missing it´s a swtich of templates as exist when we use a computer or smartphones for example, but in this case it´s more simple to have two versions of hfs and run only the one with macros or not

Even better: two HFS versions on two separate computers!

[Rapid]

By saying 'templates are based' on macros, it could only mean 'some templates depend' on macros (but only those templates that need a macro to work, like, for example, the default template). However, your latest statement is not entirely accurate, since you can have a template without macros. Otherwise, you would not be able to install or use the templates I've modified in this post HERE, which can be used with macros disabled (obviously, some features are disabled, such as the ability to delete, rename, or upload files, but it's still a template after all). I'm not looking to argue, but I do have a clear understanding of what macros are and how they work.
...

Ok, if we don't count "%item-url%" as macros, than you are right. But technically it's kind of macros too 

I like the idea to have a separate template for no-macros mode. So I will add an option "Disable macros for non-local IP" to use separate templates for local and non-local users.
It remains to add the possibility to define these separate templates.
As of start I will add template as a resource. We already have an example "dmBrowser.tpl" for download managers.

[LeoNeeson]

Ok, if we don't count "%item-url%" as macros, than you are right.

I agree that it looks similar, but '%item-url%' is one of the 'Symbols' available (Macros and Symbols are both processed at server-side). %Symbols% are much safer and already existed in very ancient versions (before Rejetto added macros in v2.3x), and are replaced by the real values at run-time (when the HTML page is built), meanwhile macro works like server-side scripting.

I like the idea to have a separate template for no-macros mode. So I will add an option "Disable macros for non-local IP" to use separate templates for local and non-local users.

I'm glad you like the idea.

For any other thing related about this, it's much better to open a new thread in 'Programmers corner', to not disturb users subscribed to this thread who are waiting for news on this issue.