Huge slowdown with FF45 and NS 2.9.0.4

[gurv]

Hello everyone.

I'm having a problem with noscript 2.9.0.4 since I upgraded to Firefox 45.
Everything was working properly with Firefox 44.

The problem appears when visiting https://particuliers.societegenerale.fr/
When I enable the domain "societegenerale.fr" in NS on this page, Firefox becomes unresponsive for about 1minute.
I notice it uses 100% of one of my cpu cores.

After this minute of unresponsiveness, Firefox offers me to download an empty file with the following name (yes it seems it uses js code as the filename, no idea why) :

Code: Select all

javascript__(function(){function i(){if(typeof XMLHttpRequest!='undefined'){return new XMLHttpRequest()}try{return new ActiveXObject(_Msxml2.XMLHTTP_)}catch(e){try{return new Active.join(_&_)}function k(a){var b={},d=(a

When I disable noscript, the webpage loads just fine.
When I use noscript 2.9.0.4 with Firefox 44, the webpage loads just fine.

I have reproduced the problem with the following configurations:
Linux Mint 17.2 / FF 45 / NS 2.9.0.4
Linux Mint 17.2 / FF 45 / NS 2.9.0.5rc1
Linux Mint 17.2 / FF 45 / NS 2.9
Windows 8 / FF 45 / NS 2.9.0.4

Additionally, I've loaded this page with the Firefox performance profiler addon and this is what it reports :
http://imgur.com/qy4X2Ry

Thank you in advance for your help

[Thrawn]

That bank is known to trigger the XSS filter:

viewtopic.php?p=80010#p80010
viewtopic.php?f=7&t=21516&p=80560

I don't know why it worked correctly in Firefox 44, but your image confirms that the slowness is occurring in the InjectionChecker. You should consider adding a filter exception or using a separate profile, as suggested in the linked threads.

[Gurv]

Thanks for the answer!
I had no idea that website had such a behaviour.

Though now that you mention it, this webpage was in fact a bit slow to load in previous Firefox versions.
However it was nowhere near as bad as it is now with FF45 (4-6s of loading vs 1 minute of 100% cpu for browser thread).
So I thought at the time that it was a problem with the bank's servers

Anyway I'll add an exception in NS for this website.
Thanks again for the clarification!

[barbaz]

Anyway I'll add an exception in NS for this website.

There is no safe exception that can be made for a case like this. As Thrawn said you are best off to create a dedicated profile for use with the bank site.