TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow. Vulnerability could be triggered from CopyRectDecoder due to incorrect value checks. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://github.com/CendioOssman/tigervnc/commit/996356b6c65ca165ee1ea46a571c32a1dc3c3821
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00039.html