Heap out-of-bounds write in LibVNCServer - CVE-2018-20020

Vulnerability identifier: #VU17124

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-2018-20020

CWE-ID: CWE-787

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 heap out-of-bounds write in inside structure in VNC client code. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.

Successful exploitation of the vulnerability may result in system compromise.

LibVNCServer
Gentoo Linux
Opensuse
Ubuntu
libvncserver (Debian package)
italc-client (Ubuntu package)
italc-master (Ubuntu package)
libitalccore (Ubuntu package)

Update to version 0.9.12.

LibVNCServer - update to 0.9.12
libvncserver (Debian package) - addressed in versions 0.9.9+dfsg2-6.1+deb8u5, 0.9.11+dfsg-1.3~deb9u1
italc-client (Ubuntu package) - update to 1:3.0.3+dfsg1-3ubuntu0.1
italc-master (Ubuntu package) - update to 1:3.0.3+dfsg1-3ubuntu0.1
libitalccore (Ubuntu package) - update to 1:3.0.3+dfsg1-3ubuntu0.1

• https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-030-libvnc-heap-out-of-bound-write/

• Multiple vulnerabilities in LibVNCServer
• OpenSUSE Linux update for LibVNCServer
• Debian update for libvncserver
• Gentoo update for ssvnc
• Ubuntu update for italc