There’s been some chatter about Signal desktop recently, so let’s clear the air. Three points:
1. The reported issues rely on an attacker already having *full access to your device* — either physically, through a malware compromise, or via a malicious application running on the same device. This is not something that Signal, or any other app, can fully protect against. Nor do we ever claim to.
reshared this
Meredith Whittaker
in reply to Meredith Whittaker • • •2. We continue working to harden our desktop build across supported operating systems and take advantage of new platform capabilities as they emerge. Those of you following our repo can follow this work there.
3. The posters who raised this issue did so without contacting us directly. Instead, they went straight to social media, in some cases using inflammatory language. And they dropped these claims over a US holiday weekend. This is the opposite of responsible disclosure.
Meredith Whittaker
in reply to Meredith Whittaker • • •Bas (Tools on Tech)
in reply to Meredith Whittaker • • •Mysk🇨🇦🇩🇪
in reply to Meredith Whittaker • • •Hi Meredith, let me address your points:
1) The issue we highlighted does not require “full” access to the device. Signal desktop stores the chat database in an unprotected area of the file system that’s accessible by any user process. This would allow any program without any special permissions or user prompts to access the database in full. This can be solved by sandboxing, which relies on the OS to prevent any process from accessing data within the sandbox.
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Draken BlackKnight
in reply to Meredith Whittaker • • •Sapient
in reply to Meredith Whittaker • • •Wasnt this first disclosed in 2018?
bleepingcomputer.com/news/secu…
Seems like its been on the back burner for a while and just recently resurfaced.
Hugo 雨果
in reply to Meredith Whittaker • • •Hugo 雨果
in reply to Meredith Whittaker • • •I am deeply worried by how you are trying to misrepresent and distort this situation. Your words are damaging my trust in Signal a lot more than the actual security issue at hand.
You claim that the attack "requires full access" (it only requires read-only access), that it cannot be avoided (other messaging clients protect against this particular scenario), and that is was disclosed irresponsibly (the issue was mentioned and circulated on twitter a year or two ago).
gregor herrmann
in reply to Meredith Whittaker • • •Lien Rag
in reply to Meredith Whittaker • • •If I'm not mistaken, it's not "full access" that is required though (i.e., no root password is necessary to access the sqlite database and the password).
Leaving such a sensitive information accessible to *any* process is sloppy.
Tio
in reply to Meredith Whittaker • •🌙 ▪️▪️▪️ 🦇 likes this.
Guillaume Ross
in reply to Meredith Whittaker • • •Hugo 雨果
in reply to Meredith Whittaker • • •The scenario that has been mentioned lately is "an attacker with temporary read-only access to the filesystem can copy session data and hijack the session indefinitely without any indication".
This CAN be mitigated, and plenty of other messaging applications have done so for many years. The most obvious solution to this particular problem is using the platform-specific keyring to store the session token so that it is encrypted at rest.
Hugo 雨果
in reply to Meredith Whittaker • • •I want to make it clear that it is theoretically possible to prevent this attack, that many other messaging clients prevent against it, and even alternative clients to Signal's network prevent it.
Flare (an alternative Signal client) DOES protect against this specific attack: gitlab.com/Schmiddiii/flare/
Your claims of "This is not something that Signal [...] can protect against" is complete BS.
Schmiddi on Mobile / Flare · GitLab
GitLabErica Marigold :vm:
in reply to Meredith Whittaker • • •AlexTECPlayz
in reply to Meredith Whittaker • • •Yeah no, this post is a big miss and reeks of sh*t. Just because OSes already have disk encryption that can be enabled, doesn't mean Signal shouldn't also at the very least, give the option to also encrypt the files that are saved/cached/whatever.
Maybe some missed the option to encrypt their system and can't be arsed to reflash their entire OS again - like me, I didn't see any option in the Debian installer to encrypt the disk or the home folder, and forgot about it, so now I'm currently not in the mood to literally reinstall the system again to manually encrypt it.
I know very well that this is risky if someone had access to the hardware, but I would have felt better if Signal Desktop was also encrypting the files.
I stopped using Signal, mostly due to its centralised manner, and the phone number requirement, and this issue that apparently has been known for years and not getting fixed, is certainly not pushing me to use Signal again. Do better.