File-format based vulns - How do IDS/IPS vendors detect them?

[Joshua Russel <joshua.russel () gmail com>]

Hi,

After the recent announcement of file-format based vulnerabilities in
MS Patch Tuesday, I was wondering how do IPS/IDS vendors claim to
protect against them (most of them like TippingPoint claim to do so).
Do they scan data transfer streams (SMTP, FTP, HTTP etc) for these
malicious files or is it a local check? If they do detect it on the
network doesn't it screw up their device due to high chance of false
positives and high resource consumption.

--Joshua