I have the same question also regarding the FW and the E-Mail Gateway.
Our initial investigations showed that the issue affected all the versions of glibc since 2.9.
This is the Verison on our MWG 7.3 and 7.6
ldd (GNU libc) 2.12
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.
So I expect the Proxies are effected by this Vulnerability unless McAfee does not modify the lib in the past.
As usual, we will not discuss,disclose or comment on vulnerabilities in this community.
Please open either a support ticket with (if not done already) or wait for SNS to be sent out/KB articles to be published.