EMET "simexecflow" mitigation alert with Firefox

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Joined: April 30th, 2014, 3:42 pm

Post Posted November 2nd, 2015, 4:39 pm

Using the latest version of Firefox on 64-bit Windows 10 Pro with Microsoft's EMET-5.2 protection enabled pretty much across the board, I am getting an alert from EMET that Firefox has "simexecflow" problem while starting the program, and it shuts the program down. Incidentally, when it happens while starting up in Sandboxie, again latest version, it actually turns off the PC abruptly without BSOD.

So, when I go into EMET and deselect the "simexecflow" column, then the problem ceases completely, with or without Sandboxie in the mix. This problem just started happening a few days ago. I do not recall installing anything in particular prior to these incidents.


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Post Posted November 2nd, 2015, 5:58 pm

You're not the first, but it appears they were using FF 41 x86.

Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20110420 SeaMonkey/2.0.14 Pinball CopyURL+ FetchTextURL FlashGot NoScript

Posts: 66
Joined: April 30th, 2014, 3:42 pm

Post Posted November 2nd, 2015, 7:59 pm

Thanks for the information. I suppose it is a bit reassuring to know that I am not the only one affected by it. It's less personal that way. Be that as it may, I'm not sure why the previous poster was unable to see the same message from EMET, which clearly identified the issue in my case so long as I was not running it in Sandboxie at the moment. As I mentioned, in Sandboxie it just up and shut down Windows, but that may be a good thing since it ends the possibility of an exploit, albeit abruptly.

It looks like that poster turned off "all" EMET protections in Firefox instead of just the offending one. Seems like throwing out the baby with the bathwater to me.

Incidentally, therube, I think you must be a regular beacon of light in this place. Take care.

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