Infinite loop in LibVNCServer - CVE-2020-14398

Vulnerability identifier: #VU29381

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-2020-14398

CWE-ID: CWE-835

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 infinite loop in libvncclient/sockets.c when closing TCP connections. A remote attacker can consume all available system resources and cause denial of service conditions.

LibVNCServer
Opensuse
Ubuntu
SIMATIC ITC2200 PRO
SIMATIC ITC2200
SIMATIC ITC1900 PRO
SIMATIC ITC1900
SIMATIC ITC1500 PRO
SIMATIC ITC1500
libvncclient1 (Ubuntu package)
libvncserver1 (Ubuntu package)

Install updates from vendor's website.

LibVNCServer - update to 0.9.13
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/57433015f856cc12753378254ce4f1c78f5d9c7b
• 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
• Multiple vulnerabilities in Siemens SIMATIC ITC
• Ubuntu update for libvncserver