CVE-2019-8268

Name: CVE-2019-8268
Creator: NVD / NIST
Published: 2019-03-08T23:29:00.623+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.92%

Last modified Jun 17, 2026

CVE-2019-8268 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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 appears to be exploitable via network connectivity. EPSS estimates a 3.92% chance of exploitation in the next 30 days.

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 appears to be exploitable via network connectivity. These vulnerabilities have been fixed in revision 1207.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

3.92%

89.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Uvnc	Ultravnc	< 1.2.2.3
Siemens	Sinumerik Access Mymachine\/P2p	< 4.8
Siemens	Sinumerik Pcu Base Win10 Software\/Ipc	< 14.00
Siemens	Sinumerik Pcu Base Win7 Software\/Ipc	<= 12.01

References

https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdfThird Party Advisory
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-015-ultravnc-off-by-one-error/Third Party Advisory
https://www.us-cert.gov/ics/advisories/icsa-20-161-06Third Party Advisory, US Government Resource
https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdfThird Party Advisory
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-015-ultravnc-off-by-one-error/Third Party Advisory
https://www.us-cert.gov/ics/advisories/icsa-20-161-06Third Party Advisory, US Government Resource

Timeline

Published: Mar 8, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-8268?

How severe is CVE-2019-8268?

CVE-2019-8268 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.92% probability of exploitation in the next 30 days.

How do I fix CVE-2019-8268?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-8268?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST