CVE-2017-18922

highpriority · track · 40EPSS 0.023 · 83 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
2.26% (83rd) EPSS
CVSS 7.5 · high
Is it mine?
138 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

9.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · CISA US
v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · Red Hat Product Security US
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-120USCWE-122USCWE-787USCWE-787USCWE-787US
04

affected products (138)

Products and version ranges known to be affected.

showing 20 of 138
05

advisories (6)

Vendor and ecosystem advisories describing this.

  • RHSA-2020:3281Red Hat Security Advisory: libvncserver security update2020-08-03csaf · redhat_csafUS

    An update for libvncserver is now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2020:3385Red Hat Security Advisory: libvncserver security update2020-08-10csaf · redhat_csafUS

    An update for libvncserver is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2020:3456Red Hat Security Advisory: libvncserver security update2020-08-17csaf · redhat_csafUS

    An update for libvncserver is now available for Red Hat Enterprise Linux 8.1 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2020:3588Red Hat Security Advisory: libvncserver security update2020-09-01csaf · redhat_csafUS

    An update for libvncserver is now available for Red Hat Enterprise Linux 8.0 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • SSA-390195SSA-390195: LibVNC Vulnerabilities in SIMATIC ITC Products2021-12-14csaf · siemens_psirtDE

    Multiple LibVNC vulnerabilities in the affected products listed below could allow remote code execution, information disclosure and Denial-of-Service attacks under certain conditions. Siemens has released updates for the affected products and recommends to update to the latest versions.

  • ICSA-21-350-12Siemens SIMATIC ITC2021-12-14icsa · cisa_csaf_otUS

    Multiple LibVNC vulnerabilities in the affected products listed below could allow remote code execution, information disclosure and Denial-of-Service attacks under certain conditions. Siemens has released updates for the affected products and recommends to update to the latest versions.

06

also known as (5)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisa_csaf_otredhat_csafsiemens_psirtNVDCVE.orgMITRE
published 2020-06-30modified 2026-06-17
09

references (54)

External citations — patches, advisories, analysis.

scry

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