What’s Vulnerable › Vulnerabilities

CVE-2019-8268

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-03-08 · updated 2026-06-17
• Weakness: CWE-193

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.

Affected products

• Siemens Sinumerik Access Mymachine/P2P: before 4.8 — fixed in 4.8
• Siemens Sinumerik Pcu Base Win10 Software/Ipc: before 14.00 — fixed in 14.00
• Siemens Sinumerik Pcu Base Win7 Software/Ipc: through 12.01
• Kaspersky Lab UltraVNC: before 1.2.2.3 — fixed in 1.2.2.3

How to fix

Upgrade to a fixed version: Siemens Sinumerik Access Mymachine/P2P 4.8; Siemens Sinumerik Pcu Base Win10 Software/Ipc 14.00; Kaspersky Lab UltraVNC 1.2.2.3. Check the vendor advisory for mitigations.

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
• https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-015-ultravnc-off-by-one-error/
• https://www.us-cert.gov/ics/advisories/icsa-20-161-06
• https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
• https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-015-ultravnc-off-by-one-error/
• https://www.us-cert.gov/ics/advisories/icsa-20-161-06

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