Kee browser extension on Firefox crashes when certain website is opened

I use Firefox with Kee Extension for KeePass, all latest versions.

When the website Aktien: Alle Aktienkurse in REALTIME - ARIVA.DE is open and I open or close KeePass, at once Firefox produces 50-90% CPU load and quickly rising memory usage.

If KeePass is already open, and then I open the mentioned website, the problem does not occur as long as I do not close KeePass.

So the problem only occurs when the mentioned website is already opened, and then I open or close KeePass.

  • It also happens if I disable all other addons in Firefox, only Kee addon is active.
  • With other websites, this is not happening.
  • It happens evety time, reproducably.
  • Sometimes, I can regularly finish Firefox (but only very slowly because of the high CPU load), sometimes it reacts so slowly that it has to be stopped via the task manager.

Can anybody confirm this bug?

Thanks for the clear bug report. I was able to reproduce the problem on that website and think that I have implemented a fix.

The fix is included in the latest development version of Kee 3.8 - Release 3.8.1 · kee-org/browser-addon · GitHub

I won’t have time to thoroughly test it for at least a week or two so it won’t make it into the upcoming Kee 3.7 but if someone can confirm the problem is resolved in that development version, that will speed along the process of releasing 3.8 to beta testers, once they’ve had a chance to test the changes in 3.7 that are rolling out now.

Installing development versions of Kee requires jumping through some hoops such as using a pre-release version of Firefox so don’t worry if you can’t test it - I will eventually get around to doing so myself.

For anyone interested in the technical details, it turns out that Firefox and Chrome inject the scripts that Kee runs on webpages into SVG images as well as webpages. I can’t find much in the way of documentation about this behaviour, nor any way to customise it but I found what I think is a way to prevent the Kee script from doing anything significant when it is mistakenly asked to execute inside an SVG.

The reason that this could lead to runaway CPU usage and memory growth is not clear but I suspect it relates to how Kee has to re-execute some parts of its startup code in certain circumstances (there are - at least in older browser versions - several bugs in Firefox and Chrome that we have to work around).

I have a further idea to reduce this impact of failed script startup which I will explore in the coming weeks and hope to include in Kee 3.8 - that might help in situations where the reason for the startup failure is not due to being injected into an SVG.

Thank you so much! Indeed, I don’t use Firefox as pre-release version. How many weeks will the official release of the bugfix take, what would you guess?

No promises but the beta version should be within 1-2 weeks. That’s much easier to use than the pre-release versions and you could switch to it now in order to get auto-updated to v1.8 as soon as I release it to beta testers. See Beta testing the Kee browser extension

Thank you, but I’m sorry, I also don’t use beta versions, because I really need stable software. What do you guess, when will the official release of version 3.81 be made?

There’s only been one bug in one of our beta versions over the past few years so it’s very stable - that’s why I’m not releasing v3.8 immediately.

I don’t know when I’ll release v3.8 to the “stable” update channel - it depends on how many people test the beta version and any feedback they provide. In the past, that amount of time has been between 1 and 24 weeks for varying reasons so I can’t definitively answer your question I’m afraid.