Just having 3.1.1 in portage should be enough.
The changelog mentions:
"Fixed a buffer overflow error which could have allowed a denial of service under unusual server configurations."
I don't know if this could be seen as a security bug...
Server DoS is security relevant I think.
Looks like an old VMWare CVE-2007-0062. Some more notes in:
Arches please test and mark stable 3.1.1 as it resolves a DoS through buffer overflow (alledgedly can only be triggered under "unusual server configurations").
ppc and ppc64 done
Stable on alpha.
Stable for HPPA.
mips doesn't stabilize