An Italian cybersecurity passionate discovered that it was possible to recover the expired messages from Signal version 1.14.3,
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Signal Desktop – Recover Expired Messages
Leonardo Porpora – ‘n0sign4l’
1.14.3 and prior
Public Disclosure: 17/08/2018
Open Whisper System
Signal version 1.14.3 was vulnerable to the recovery of expired messages.
When I reported the vulnerability to the Signal Security Team, its experts fixed it in a very short time, but the fix was partial; in fact version 1.14.4, even though fixed one vulnerability, was still vulnerable to a different attack. I reported the new issue to the security team and version 1.15.0-beta.10 finally addressed the problem.
Everything started from a message that was not cleared from the preview of Signal-Desktop
The version 1.14.4 fixed this issue but I wanted to try if it was possible to recover messages again from the logs and they were still there. The issue was related to IndexedDB not deleting messages predictably.
Below a video PoC of the vulnerability:
Update Signal to version 1.15.0-beta.10
I am very happy to have contributed to the security of Signal, an application that I use every day to talk with my friends, professors…
My contribution was also possible because this is an open-source project and other than just reporting the security hole I had the opportunity to analyze the source code and highlight the flaw.
This is a small example of how effective is the open-source model and I hope everyone can understand the benefits of the community contribution in data protection field so that everybody can provide contributions.
Sorry I can not hear you, there’s interference
About the author Leonardo Porpora
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