Buffer overflow in LibVNCServer - CVE-2020-14403

Vulnerability identifier: #VU29376

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-14403

CWE-ID: CWE-119

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing encodings in libvncserver/hextile.c. A remote attacker can pass specially crafted data to the server, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

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

Install updates from vendor's website.

LibVNCServer - update to 0.9.13
libvncserver (Alpine package) - update to 0.9.13-r0
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/74e8a70f2c9a5248d6718ce443e07c7ed314dfff
• https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13

• Multiple vulnerabilities in LibVNCServer
• Buffer overflow in libvncserver (Alpine package)
• Multiple vulnerabilities in Siemens SIMATIC ITC
• Ubuntu update for libvncserver