RHSA-2021:1811: Red Hat Security Advisory: libvncserver security update

An update for libvncserver is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.LibVNCServer is a C library that enables you to implement VNC server functionality into own programs. Security Fix(es):

• libvncserver: uninitialized memory contents are vulnerable to Information Leak (CVE-2018-21247)
• libvncserver: buffer overflow in ConnectClientToUnixSock() (CVE-2019-20839)
• libvncserver: libvncserver/rfbregion.c has a NULL pointer dereference (CVE-2020-14397)
• libvncserver: libvncclient/rfbproto.c does not limit TextChat size (CVE-2020-14405)
• libvncserver: libvncserver/rfbserver.c has a divide by zero which could result in DoS (CVE-2020-25708) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Additional Changes: For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.4 Release Notes linked from the References section. Related CVEs:
• CVE-2018-21247: libvncserver: uninitialized memory contents are vulnerable to Information Leak
• CVE-2019-20839: libvncserver: buffer overflow in ConnectClientToUnixSock()
• CVE-2020-14397: libvncserver: libvncserver/rfbregion.c has a NULL pointer dereference
• CVE-2020-14405: libvncserver: libvncclient/rfbproto.c does not limit TextChat size
• CVE-2020-25708: libvncserver: libvncserver/rfbserver.c has a divide by zero which could result in DoS