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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.031 (87.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.031 · change: 0.000
Affected products
- Tigervnc
- Debian Linux — versions 9.0
- openSUSE Leap — versions 15.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/TigerVNC/tigervnc/releases/tag/v1.11.0 (Third Party Advisory, Release Notes)
- github.com/TigerVNC/tigervnc/commit/f029745f63ac7d22fb91639b2cb5b3ab56134d6e (Patch, Third Party Advisory)
- github.com/TigerVNC/tigervnc/commit/b30f10c681ec87720cff85d490f67098568a9cba (Patch, Third Party Advisory)
- github.com/TigerVNC/tigervnc/commit/20dea801e747318525a5859fe4f37c52b05310cb (Patch, Third Party Advisory)
- github.com/TigerVNC/tigervnc/commit/7399eab79a4365434d26494fa1628ce1eb91562b (Patch, Third Party Advisory)
- bugzilla.opensuse.org/show_bug.cgi (Third Party Advisory, Issue Tracking)
- lists.debian.org/debian-lts-announce/2020/10/msg00007.html (mailing-list, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-10/msg00025.html (vendor-advisory, Mailing List, Third Party Advisory, Broken Link)
- lists.opensuse.org/opensuse-security-announce/2020-11/msg00024.html (vendor-advisory, Mailing List, Third Party Advisory, Broken Link)
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.