Heimdal is a free implementation of Kerberos 5.
Heimdal does not properly perform certain consistency checks for cross-realm requests, which allows remote attackers with control of a realm to impersonate others in the cross-realm trust path.
Remote attackers with control of a realm may be able to impersonate other users in the cross-realm trust path.
A workaround is not currently known for this issue. All users are advised to upgrade to the latest version of the affected package.
Heimdal users should upgrade to version 0.6.1 or later:
# emerge sync
# emerge -pv ">=app-crypt/heimdal-0.6.1"
# emerge ">=app-crypt/heimdal-0.6.1"