14 DAY TRIAL // This is quite serious. Such a flaw can be used by hackers to compromise a user's system. I advise you to fix the program's bug first, before using it again. If you fail to do so - it's your risk!
I've gotten this info from the Secunia website. They have all sorts of useful information on program vulnerabilities. So, a flaw has been disclosed in the eCentrex VOIP Client Component ActiveX; and here comes the techie part: it is due to a boundary error within the eCentrex SIP UA Com Module (e800) (euacom.dll) when handling an overly long argument passed to the "ReInit()" method of the eCentrex VOIP Client Component ActiveX control (uacomx.ocx). This can be exploited to cause a stack-based buffer overflow and allows execution of arbitrary code. Also, as I've seen on the same site, this vulnerability is confirmed in eCentrex VOIP Client Component version 2.0.1.0 in combination with the eCentrex SIP UA Com Module (e800) version 2.1.1.1. The flaw may not be limited to these versions.
The vendor has released no patch yet, but a solution would be to set the kill-bit for the affected ActiveX control. If you are not very tech-savvy but you, nevertheless wish to fix this problem, get someone that knows what he's doing, because you don't want to screw this up even more! The vulnerability has been ranked as highly critical by Secunia experts, so do take care, as you have been warned!
If you do know what you are doing, then you can click on this link to see what the original advisory has to say about the remote buffer overflow exploit. Also, you may want to get some support from the ones that have initially developed the product, eCentrex, that is, so here is a link to their official website, from where you can get their contact info.