Security researcher Harry Sintonen disclosed that the macOS desktop Signal app doesn't actually delete messages when they're deleted in the UI of the app.
It’s not a good sign for Signal to take this long to fix things. Wonder what’s happening over there.
Isn’t this a non-issue if you restart the Signal app or use it often though?
Restrictions
------------
This vulnerability is mitigated by several factors:
1. The database is encrypted. To extract any deleted messages, the attacker will
have to defeat the encryption. This requires capabilities and expertise.
2. Active Signal use will reach the Write-Ahead log page limit fast, leading to
merging of log fairly regularly.
3. Signal app restart will commit the Write-Ahead Log, deleting the messages.
While it’s not nice from Signal to not answer I know this is something a lot of big open source projects have been struggling with since people spam them with AI generated content.
But then again I don’t see this impacting 99% of all Signal users on macOS. Still an interesting find though.
When it comes to apps like Signal, there should not be an “issue” or an issue that would need any mitigating factors in the first place.
I agree this should be fixed but I personally don’t like the way OP wrote this. Maybe it’s just me but it sounded more dramatic than it actually is.
I’m not involved in Signals development but I can imagine there are bigger issues than this and as a Signal user I’d want them to be ranked higher and fixed first. A scenario where an attacker has to defeat encryption, the user never restarts Signal (which also means never restarting the computer) and doesn’t use Signal doesn’t sound like it’s urgent.
Then again to fix this (if it’s really true) you’d probably only need a few lines of code. If I were the security researcher who has found this I’d probably write a patch myself and open a PR.