4 ms·
Aren’t notifications supposed to be encrypted for Signal?
by frizlab 6mo ago
Aren’t notifications supposed to be encrypted for Signal?
- dewey 6mo ago[dead]
- shantara 6mo agoiOS stores the previously displayed notifications in an internal database, which was used to access the data. It’s outside of Signal’s control, they recommend disabling showing notification content in their settings to prevent this attack vector
- exitb 6mo agoThey do control the content on the notification. It's a bit odd to put the sensitive text in the notification only to recommend disabling it at the system level.
- frizlab 6mo agoThey do not. They send encrypted notifications. It’s the OS that stores them unencrypted. It’s the OS at fault here IMHO.
- throawayonthe 6mo agoi think they're replying to the "recommendation" part -- if it was recommended, why isn't it the safe default? i haven't actually seen signal or anyone adjacent recommend that previously though, idk where that claim came from
- shantara 6mo agoSorry, the “recommended” was a bad wording on my part. The recommendation comes from the 404 Media article who did the expose on this incident, not Signal itself. I’ve checked the Signal documentation page, and there’s no mention of the privacy implications of the setting: https://support.signal.org/hc/en-us/articles/360043273491-In-App-Notification-Options#ios_notification_options https://support.signal.org/hc/en-us/articles/360043273491-In...
- llacane 6mo agoSignal does NOT send encrypted notification, they send a blank notification that act like a ping, the actual encrypted data is then fetched by the app itself.
- kccqzy 6mo agoNo. They recommended disabling it at the app level. Only the Signal app can control whether the message contents are included in the notifications.
- makosdv 6mo agoYou can choose what to show in the notification and there is an option to include the message, so I'm guessing that allowed some unencrypted incoming messages to be read.
- frizlab 6mo agoSibling comment explains. The notification does arrive encrypted and is decrypted by an app extension (by Signal), however, if the message preview is shown, it is stored unencrypted by iOS. It is that storage that is accessed.
- butvacuum 6mo agoit seems iOS will drop previews into an unencrypted section. which, Is how I expected iOS notification previews to work without unlocking the phone
- krisknez 6mo agoThis kind of vulnerability is not tied to Signal but all apps which send notification.
- throawayonthe 6mo agoThey are; “Messages were recovered from Sharp’s phone through Apple’s internal notification storage—Signal had been removed, but incoming notifications were preserved in internal memory. Only incoming messages were captured (no outgoing).” ie the messages recovered were 1. incoming 2. stored by the OS after decryption i also was spooked by the headline :p