The rfbProcessClientNormalMessage function in libvncserver/rfbserver.c in LibVNCServer 0.9.9 and earlier allows remote attackers to cause a denial of service (divide-by-zero error and server crash) via a zero value in the scaling factor in a (1) PalmVNCSetScaleFactor or (2) SetScale message.
lists.opensuse.org/opensuse-updates/2015-12/msg00022.html
seclists.org/oss-sec/2014/q3/639
secunia.com/advisories/61506
secunia.com/advisories/61682
www.debian.org/security/2014/dsa-3081
www.ocert.org/advisories/ocert-2014-007.html
www.openwall.com/lists/oss-security/2014/09/25/11
www.securityfocus.com/bid/70094
www.ubuntu.com/usn/USN-2365-1
github.com/newsoft/libvncserver/commit/05a9bd41a8ec0a9d580a8f420f41718bdd235446
lists.debian.org/debian-lts-announce/2019/10/msg00042.html
security.gentoo.org/glsa/201507-07
usn.ubuntu.com/4587-1/