Interesting - I wonder if this exploit has been used in the wild?

Also: 

The more significant impact of Check Point’s research may be the fallout created if other apps that bundle UNACEV2 suffer from similar traversal vulnerabilities.

I use PowerArchiver and it contains a UNACEV2.dll (though it's from 2007, not 2005).  I'll have to ask about this on their forum.  In the meantime I have removed the DLL.  The program seems to still run fine - I assume it only loads the DLL is it has to deal with an ACE archive. If you use any archiving utility it might not be a bad idea to check if that DLL is used.

I have been using and am happy with SafeInCloud.

It's not open source, but there is no online subscription - online storage is your choice of DropBox, Google Drive, or a couple others.  You can also use your own WebDAV server if you want.  The mobile app versions are around $5 at whichever app store (with the occasional sale).  There are Windows and Mac desktop apps that are free.

However, I can't speak to its browser or automatic password fill-in integration (which it claims to have) as I have never tried those features.

You can try the Android or iOS app free for a couple weeks.