The urlopen function in pym/portage/util/_urlopen.py in Gentoo Portage 2.1.12, when using HTTPS, does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and modify binary package lists via a crafted certificate.

Multiple untrusted search path vulnerabilities in Portage before 2.1.4.5 include the current working directory in the Python search path, which allows local users to execute arbitrary code via a modified Python module that is loaded by the (1) ys-apps/portage, (2) net-mail/fetchmail, (3) app-editors/leo ebuilds, and other ebuilds.