Home / Advisories / KLCERT advisories / KLCERT-19-015: UltraVNC Off-by-one Error

KLCERT-19-015: UltraVNC Off-by-one Error

Kaspersky Lab publishes information on newly identified vulnerabilities in order to raise user awareness of the IT security threats detected. Kaspersky Lab does not make any guarantees in respect of information received from vendors of products in which vulnerabilities have been identified, which is included in the following sections of the advisory: Affected Products, Vendor Mitigation.

CVE-IDS CVE-2019-8268
Publication date 2019.03.01
Researcher Pavel Cheremushkin, Kaspersky Lab ICS CERT
Description UltraVNC revision 1206 has multiple off-by-one vulnerabilities in VNC client code connected with improper usage of ClientConnection::ReadString function, which can potentially result code execution. This attack appear to be exploitable via network connectivity. These vulnerabilities have been fixed in revision 1207.
Impact Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code.
CVSS v3 Base Score: 10.0
Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Exploitability Remotely
Difficulty Low
User interaction None
Existence of exploit Unknown
Affected products
Affected products UltraVNC before
Vendor mitigation Update UltraVNC to revision 1207.
Timeline Jan 2019 – Vulnerabilities reported
Feb 2019 – Vendor releases patch
Mar 2019 – Advisory published