Gentoo Gentoolkit contains a flaw that may allow a malicious user to overwrite arbitrary file reguardless of permissions. The issue is triggered when qpkg does not check permissions before writing to files in the /tmp directory occurs. It is possible that the flaw may allow a user to overwrite a file that has root privilages resulting in a loss of integrity.
Upgrade to version "0.2.0_pre8-r1" or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.