Executive TL;DR:

• A stable Firefox identifier can link all private Tor identities.
• This vulnerability poses a significant threat to user anonymity.
• Users can mitigate the risk by exiting Tor Browser at the end of each session.

The Buzz Score:

The Internet’s Verdict: 70% Hyped, 30% Skeptical

Forum Reactions:

Users are concerned about the implications of this vulnerability. As one user noted:

Why would this company report this vulnerability to Mozilla if their product is fingerprinting? Isn’t it better for the business (albeit unethical) to keep the vulnerability private, to differentiate from the competitors?

Another user emphasized the importance of proper browser hygiene:

Make sure to exit Tor Browser at the end of a session. Make sure not to mix two uses in one session.

Technical Implications:

The identifier can persist as long as the Firefox process remains running. However, it does not persist past browser restart, which reduces its usefulness to attackers.

Some users are looking for academic research on this topic, beyond activist groups like the EFF.

Focus Keyword: Tor Browser