A malicious VNC client can trigger multiple DoS conditions on the VNC server by advertising a large screen size, ClientCutText message length and/or a zero scaling factor parameter (CVE-2014-6053, CVE-2014-6054).
A malicious VNC client can trigger multiple stack-based buffer overflows by passing a long file and directory names and/or attributes (FileTime) when using the file transfer message feature (CVE-2014-6055).
The krfb package is built with a bundled copy of libvncserver.