CVE-2019-8258

Name: CVE-2019-8258
Creator: NVD / NIST
Published: 2019-03-05T15:29:00.32+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 4.43%

Last modified Jun 17, 2026

CVE-2019-8258 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. UltraVNC revision 1198 has a heap buffer overflow vulnerability in VNC client code which results code execution. This attack appears to be exploitable via network connectivity. EPSS estimates a 4.43% chance of exploitation in the next 30 days.

Description

UltraVNC revision 1198 has a heap buffer overflow vulnerability in VNC client code which results code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1199.

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

4.43%

90.2th 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-19-004-ultravnc-heap-based-buffer-overflow/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-19-004-ultravnc-heap-based-buffer-overflow/Third Party Advisory
https://www.us-cert.gov/ics/advisories/icsa-20-161-06Third Party Advisory, US Government Resource

Timeline

Published: Mar 5, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-8258?

How severe is CVE-2019-8258?

CVE-2019-8258 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 4.43% probability of exploitation in the next 30 days.

How do I fix CVE-2019-8258?

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-2019-8258?

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

Scan your code now

Source: NVD / NIST