An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c.
https://usn.ubuntu.com/4434-1/
https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13
https://github.com/LibVNC/libvncserver/commit/57433015f856cc12753378254ce4f1c78f5d9c7b
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html