Out-of-bounds write in UltraVNC - CVE-2019-8266
Published: November 25, 2019 / Updated: November 27, 2019
Vulnerability identifier: #VU22973
CSH Severity: Medium
CVSS v4: 7.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-8266
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error connected with improper usage of "ClientConnection::Copybuffer" function in VNC client code. A remote attacker that controls a malicious VNC server can trick a user to connect to it, trigger out-of-bounds write and execute arbitrary code on the target system.
Affected software
UltraVNC
How to mitigate CVE-2019-8266
Install updates from vendor's website.
UltraVNC - update to 1.2.2.3