Long Wiki Edits Thread

Could you review Account and Mobile Security: Difference between revisions - Whonix please? @HulaHoop

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Is this a solution to 20 years of censorship of Tor exit nodes?

Bypassing Tor Exit Blocking

Tor exit blocking, in which websites disallow clients arriving from Tor, is a growing and potentially existential threat to the anonymity network. We introduce two architectures that provide ephemeral exit bridges for Tor which are difficult to enumerate and block. Our techniques employ a micropayment system that compensates exit bridge operators for their services, and a privacy-preserving reputation scheme that prevents freeloading. We show that our exit bridge architectures effectively thwart server-side blocking of Tor with little performance overhead.

Code here:

This repo contains two independent packages, eebt and hebtor. To be specific, eebt corresponds to our first publication, Ephemeral Exit Bridges for Tor (DSN2020), and hebtor corresponds to our second publication, Bypassing Tor Exit Blocking with Exit Bridge Onion Services (CCS2020). Both packages are fully open-sourced under GPLv2 license.

Maybe you could promote it on official social media accounts?

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Could you move this please to a separate forum thread in development forum?

Not really as adding a user payment system brings its own set of anonymity problems. Also providing a public database of exit nodes was a conscious decision by TPO. They claimed exit nodes could be enumerated by third parties anyway. The current workarounds we documented are more practical and work today.

Any reason not to delete https://www.whonix.org/wiki/Deprecated?

Reason: https://www.whonix.org/wiki/Special:SpecialPages has many reports such as for example https://www.whonix.org/wiki/Special:WantedPages. Easy tools to get clear overviews of what’s broken in the wiki. wiki/Deprecated shows a lot stuff that needs fixing but then isn’t worth fixing as currently not needed.

Maybe a better way to keep it would be to clear the page i.e. to remove all contents with nothing. Then it would be more accessible in the wiki history if needed again.

Viewing these special pages requires user account at least. Maybe even admin account. Deactivated for anon-users to reduce server load (some automated bots kept comparing every wiki history revision with every other wiki history revision which expands exponentially).

Thank you! However, to avoid duplicated discussion, I’d suggest for next time to move the existing post to a new forum topic (+ edit if desired). Can I delete it from here?

Sure - was looking for the move button, but couldn’t see it. :slight_smile:

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We rarely go back and use any of that material there, so I think you can clear out the attic and either a) delete it all or b) delete the page entirely.

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Great, done. :slight_smile:

2 posts were split to a new topic: Wiki Footnotes

new wiki pages:

moved to its own wiki page:

new wiki page:

new wiki page:

I don’t think we properly referenced Rowhammer attacks anywhere? Where should this go?

It turns out DDR4 ain’t so protected after all.

Rowhammer exploits that allow unprivileged attackers to change or corrupt data stored in vulnerable memory chips are now possible on virtually all DDR4 modules due to a new approach that neuters defenses chip manufacturers added to make their wares more resistant to such attacks.

Rowhammer attacks work by accessing—or hammering—physical rows inside vulnerable chips millions of times per second in ways that cause bits in neighboring rows to flip, meaning 1s turn to 0s and vice versa. Researchers have shown the attacks can be used to give untrusted applications nearly unfettered system privileges, bypass security sandboxes designed to keep malicious code from accessing sensitive operating system resources, and root or infect Android devices, among other things.

Research published on Monday presented a new Rowhammer technique. It uses non-uniform patterns that access two or more aggressor rows with different frequencies. The result: all 40 of the randomly selected DIMMs in a test pool experienced bitflips, up from 13 out of 42 chips tested in previous work from the same researchers.

“We found that by creating special memory access patterns we can bypass all mitigations that are deployed inside DRAM,” Kaveh Razavi and Patrick Jattke, two of the research authors, wrote in an email. “This increases the number of devices that can potentially be hacked with known attacks to 80 percent, according to our analysis. These issues cannot be patched due to their hardware nature and will remain with us for many years to come.”

Considering network-based attacks are feasible, this is a major issue to put it mildly i.e. they don’t need local access to your machine or to fool you into running dodgy code on websites or via apps.

This is a hacker’s delight for advanced adversaries since it blows apart any sandboxing, VM separation etc.

See:

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Existing DisposableVMs risk leaking various information (a known problem) → Reduce leakage of disposable VM content and history into dom0 filesystem · Issue #4972 · QubesOS/qubes-issues · GitHub

Some Whonix users will probably want a “paranoid mode” or similar for launching of disposable Whonix-WS using this method? →

notes/Really_Disposable_Qubes.md at master · unman/notes · GitHub

Disposable qubes

In normal use qubes are created on, and changes written to, the disk. There is also extensive logging and signs of the qube are scattered in a number of places. Sometimes, you want to create a qube which does not leave these traces.
You can do this relatively simply, by creating a RAM based storage area and using it for a new storage pool. The qube will persist until the RAM disk is deleted, or the machine is shut down.

A script like this in dom0, will create tmpfs RAM disk, create a new storage pool, and create a new qube using that pool.

You can remove the qube, and some of the associated artifacts by script in dom0.

None of this is forensically reliable, although it is better than using a standard pool. (Refer to this issue, particularly if you are using Xfce, and check the associated issues.) Also, the scripts themselves will be on the disk, which may require some explanation.

Given it is scripts in dom0, users would have to do that manually, but it’s probably worth referencing this procedure here for advanced users (although I haven’t yet tested it for Whonix 16):

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Yes.

Could you please e-mail me? @torjunkie