Vulnerability in Tigervnc

CVE-2020-26117

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

Vulnerability class: Improper Certificate Validation

EPSS: 0.031 (86.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Release Notes)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Issue Tracking)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Mailing List, Third Party Advisory, Broken Link, x_refsource_SUSE)
  • cve@mitre.org (vendor-advisory, Mailing List, Third Party Advisory, Broken Link, x_refsource_SUSE)

Frequently asked questions

What is CVE-2020-26117?
CVE-2020-26117 is a high-severity vulnerability in Tigervnc, classified under Improper Certificate Validation. CVSS score: 8.1/10. Published 2020-09-27.
How severe is CVE-2020-26117?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2020-26117 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.