NULL pointer dereference in LibVNCServer - CVE-2020-14397

Vulnerability identifier: #VU29382

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-14397

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in libvncserver/rfbregion.c. A remote attacker can perform a denial of service (DoS) attack.

LibVNCServer
libvncserver (Alpine package)
libvncserver (Red Hat package)
libvncclient1 (Ubuntu package)
libvncserver1 (Ubuntu package)
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Opensuse
Ubuntu
SIMATIC ITC2200 PRO
SIMATIC ITC2200
SIMATIC ITC1900 PRO
SIMATIC ITC1900
SIMATIC ITC1500 PRO
SIMATIC ITC1500

Install update from vendor's website.

LibVNCServer - update to 0.9.13
libvncserver (Alpine package) - update to 0.9.13-r0
libvncserver (Red Hat package) - update to 0.9.11-17.el8
SIMATIC ITC2200 PRO - update to
libvncclient1 (Ubuntu package) - addressed in versions 0.9.10+dfsg-3ubuntu0.16.04.5, 0.9.11+dfsg-1ubuntu1.3, 0.9.12+dfsg-9ubuntu0.2
libvncserver1 (Ubuntu package) - addressed in versions 0.9.10+dfsg-3ubuntu0.16.04.5, 0.9.11+dfsg-1ubuntu1.3, 0.9.12+dfsg-9ubuntu0.2
SIMATIC ITC2200 PRO - update to 3.2.1.0
SIMATIC ITC2200 - update to 3.2.1.0
SIMATIC ITC1900 PRO - update to 3.2.1.0
SIMATIC ITC1900 - update to 3.2.1.0
SIMATIC ITC1500 PRO - update to 3.2.1.0
SIMATIC ITC1500 - update to 3.2.1.0

• https://github.com/LibVNC/libvncserver/commit/38e98ee61d74f5f5ab4aa4c77146faad1962d6d0
• https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13

• Multiple vulnerabilities in LibVNCServer
• OpenSUSE Linux update for LibVNCServer
• OpenSUSE Linux update for LibVNCServer
• OpenSUSE Linux update for LibVNCServer
• NULL pointer dereference in libvncserver (Alpine package)
• Red Hat Enterprise Linux 8 update for libvncserver
• Multiple vulnerabilities in Siemens SIMATIC ITC
• Ubuntu update for libvncserver