HOME VULNERABILITIESCVE-2017-18922

CRITICAL

CVE-2017-18922

CWE-787Published: June 30, 2020· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

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.

Technical Analysis

CVE-2017-18922 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Canonical1 product(s)

ubuntu linux

Fedora1 product(s)

fedora

libvncserver_project1 product(s)

libvncserver

openSUSE1 product(s)

leap

siemens12 product(s)

simatic itc1500 firmwaresimatic itc1500simatic itc1500 pro firmwaresimatic itc1500 prosimatic itc1900 firmwaresimatic itc1900simatic itc1900 pro firmwaresimatic itc1900 prosimatic itc2200 firmwaresimatic itc2200simatic itc2200 pro firmwaresimatic itc2200 pro

Source: NVD CPE · 21 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf

PATCHhttps://github.com/LibVNC/libvncserver/commit/aac95a9dcf4bbba87b76c72706c3221a842ca433

PATCHhttps://usn.ubuntu.com/4407-1/

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf

PATCHhttps://github.com/LibVNC/libvncserver/commit/aac95a9dcf4bbba87b76c72706c3221a842ca433

PATCHhttps://usn.ubuntu.com/4407-1/

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html

ADVISORYhttp://www.openwall.com/lists/oss-security/2020/06/30/3

ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=1852356

ADVISORYhttps://www.openwall.com/lists/oss-security/2020/06/30/2

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html

ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html

ADVISORYhttp://www.openwall.com/lists/oss-security/2020/06/30/3

ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=1852356

ADVISORYhttps://www.openwall.com/lists/oss-security/2020/06/30/2

All References (26)

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.htmlMailing List · Third Party Advisory

→

http://www.openwall.com/lists/oss-security/2020/06/30/3Mailing List · Third Party Advisory

→

https://bugzilla.redhat.com/show_bug.cgi?id=1852356Issue Tracking · Third Party Advisory

→

https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdfPatch · Third Party Advisory

→

https://github.com/LibVNC/libvncserver/commit/aac95a9dcf4bbba87b76c72706c3221a842ca433Patch · Third Party Advisory

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F6FUH4EFK4NAP6GT4TQRTBKWIRCZLIY/

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVP7TJVYJDXDFRHVQ3ENEN3H354QPXEZ/

→

https://usn.ubuntu.com/4407-1/Patch · Third Party Advisory

→

https://www.openwall.com/lists/oss-security/2020/06/30/2Mailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00020.htmlMailing List · Third Party Advisory

→

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00028.htmlMailing List · Third Party Advisory

Quick Facts

CVE IDCVE-2017-18922

CVSS Score9.8 / 10

SeverityCRITICAL

WeaknessCWE-787

CISA KEVNo

Affected5 vendor(s)

PublishedJun 30, 2020

Related CVEs (CWE-787)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2017-18922 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.

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