KDE is a feature-rich graphical desktop environment for Linux and Unix-like Operating Systems. KDE provided KIOslaves for many protocols in the kdelibs package, one of them being FTP. These are used by KDE applications such as Konqueror.
The FTP KIOslave fails to properly parse URL-encoded newline characters.
An attacker could exploit this to execute arbitrary FTP commands on the server and due to similiarities between the FTP and the SMTP protocol, this vulnerability also allows an attacker to connect to a SMTP server and issue arbitrary commands, for example sending an email.
There is no known workaround at this time.
All kdelibs users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose kde-base/kdelibs