CVE-2017-18635

Exp

An XSS vulnerability was discovered in noVNC before 0.6.2 in which the remote VNC server could inject arbitrary HTML into the noVNC web page via the messages propagated to the status field, such as the VNC server name.

Published: 2019-09-25 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-18635 is rated High Exploit Risk (69.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 4.81%, 91th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2017-18635

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2017-18635

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 6.49% 4.81% -1.68%
2 2026-05-29 8.31% 6.49% -1.81%
3 2026-05-26 — 8.31% —

Full EPSS history (58 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-18635

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2017-18635

GitHub Security Advisory for CVE-2017-18635

GHSA-49rv-g7w5-m8xx · Severity: medium · Ecosystem: npm — Cross-Site Scripting in @novnc/novnc

OS Trackers for CVE-2017-18635

vendor priority summary link
debian not yet assigned CVE-2017-18635 not yet assigned priority: Debian including 1 source packages (novnc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-18635
redhat medium — https://access.redhat.com/security/cve/CVE-2017-18635
suse medium CVE-2017-18635 severity moderate: SUSE including 1 source package names (novnc), 9 product×package rows across 9 product lines (HPE Helion OpenStack 8, HPE Helion OpenStack Cloud 8, … (9 product lines)): Known Not Affected 9. https://www.suse.com/security/cve/CVE-2017-18635/
ubuntu medium CVE-2017-18635 medium priority: Ubuntu including 1 source packages (novnc), 18 status rows across 18 suites (bionic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 14, DNE 1, needed 1, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2017-18635

Affected software / configurations for CVE-2017-18635

Vendor Product Version Raw CPE
novnc novnc < 0.6.2 cpe:2.3:a:novnc:novnc:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
redhat openstack 13 cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:*

References for CVE-2017-18635

URL Tags
https://access.redhat.com/errata/RHSA-2020:0754 Third Party Advisory
https://bugs.launchpad.net/horizon/+bug/1656435 Issue Tracking Third Party Advisory
https://github.com/ShielderSec/cve-2017-18635 Third Party Advisory
https://github.com/novnc/noVNC/commit/6048299a138e078aed210f163111698c8c526a13#diff-286f7dc7b881e942e97cd50c10898f03L534 Patch Third Party Advisory
https://github.com/novnc/noVNC/issues/748 Patch Third Party Advisory
https://github.com/novnc/noVNC/releases/tag/v0.6.2 Release Notes Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/10/msg00004.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/12/msg00024.html Mailing List Third Party Advisory
https://usn.ubuntu.com/4522-1/ Third Party Advisory
https://www.shielder.it/blog/exploiting-an-old-novnc-xss-cve-2017-18635-in-openstack/ Exploit Third Party Advisory
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