You should read the article. This isn't /mnt but fs/mnt.
In this particular scenario, the article describes the use of FUSE for mounting the files. FUSE stands for "Filesystem in Userspace". This, thankfully, doesn't force running a web browser as root, which would be required in your scenario.
> doesn't force running a web browser as root, which would be required in your scenario.
It would not in any way shape or form be required in my scenario. Please re-read the basics of file permissions on POSIX.
We are asking the question: "Does this expose additional potential security vulnerabilities not exposed with the cookies existing purely in the normal cookie store?"
Our possible vectors of attack are a compromised root owned service and a compromised user owned service. Both of those vectors would allow the cookie store to be exfiltrated regardless of whether this extension is used.
Ergo, this extension does not create any additional security vulnerabilities in that regard.
In this particular scenario, the article describes the use of FUSE for mounting the files. FUSE stands for "Filesystem in Userspace". This, thankfully, doesn't force running a web browser as root, which would be required in your scenario.