Setuptools is a manager for Python packages.
Setuptools does not check the integrity of downloaded Python packages.
A remote attacker could perform man-in-the-middle attacks to execute arbitrary code with the privileges of the process.
There is no known workaround at this time.
All Setuptools users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=dev-python/setuptools-0.8-r1"