Firefox Master Password System Has Been Poorly Secured for the Past 9 Years, Researcher Says (bleepingcomputer.com)
Catalin Cimpanu, writing for BleepingComputer: For at past nine years, Mozilla has been using an insufficiently strong encryption mechanism for the "master password" feature. Both Firefox and Thunderbird allow users to set up a "master password" through their settings panel. This master password plays the role of an encryption key that is used to encrypt each password string the user saves in his browser or email client. Experts have lauded the feature because up until that point browsers would store passwords locally in cleartext, leaving them vulnerable to malware or attackers with physical access to a victim's computer. But Wladimir Palant, the author of the AdBlock Plus extension, says the encryption scheme used by the master password feature is weak and can be easily brute-forced. "I looked into the source code," Palant says, "I eventually found the sftkdb_passwordToKey() function that converts a [website] password into an encryption key by means of applying SHA-1 hashing to a string consisting of a random salt and your actual master password."
So what? Yes, SHA-1 is a bit dated and is definitely not future-proof, but so far only second image type of attack has been shown for it (and it took immense amount of computational resources), and reversing is still not practically possible. Heck, even MD5 would be sort of OK for personal use (no one keeps, or, is ought to keep, top-secret passwords in browser anyway).
The fact that Firefox still uses SHA-1 just means that it's time (OK, it's time for 2—8 years already) to move to more secure hashes, nothing more.
SHA1 is not broken for this use. If the password is weak, you could brute-force it, sure. But then the user already has a problem. If the password is strong, then this is perfectly secure. Of course, using Argon 2 would be better, bit if the password is really weak, that can only do so much to make it more secure.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.