What’s Vulnerable › Vulnerabilities

CVE-2019-8261

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-03-05 · updated 2026-06-17
• Weakness: CWE-125

Description

UltraVNC revision 1199 has a out-of-bounds read vulnerability in VNC code inside client CoRRE decoder, caused by multiplication overflow. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1200.

Affected products

• Kaspersky Lab UltraVNC: before 1.2.2.3 — fixed in 1.2.2.3

How to fix

Upgrade to a fixed version: Kaspersky Lab UltraVNC 1.2.2.3. Check the vendor advisory for mitigations.

References

• https://cert-portal.siemens.com/productcert/pdf/ssa-286838.pdf
• https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
• https://cert-portal.siemens.com/productcert/pdf/ssa-940818.pdf
• https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-007-ultravnc-out-of-bound-read/
• https://us-cert.cisa.gov/ics/advisories/icsa-21-131-11
• https://www.us-cert.gov/ics/advisories/icsa-20-161-06
• https://cert-portal.siemens.com/productcert/pdf/ssa-286838.pdf
• https://cert-portal.siemens.com/productcert/pdf/ssa-927095.pdf
• https://cert-portal.siemens.com/productcert/pdf/ssa-940818.pdf
• https://ics-cert.kaspersky.com/advisories/klcert-advisories/2019/03/01/klcert-19-007-ultravnc-out-of-bound-read/
• https://us-cert.cisa.gov/ics/advisories/icsa-21-131-11
• https://www.us-cert.gov/ics/advisories/icsa-20-161-06

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