CVE-2022-36436Public exploitNetwork attack vector

Unauthenticated VNC access via None security type

Published Sep 14, 2022 · Updated Aug 3, 2024

Authentication bypass in VNCServerAuthenticator in OSU Open Source Lab VNCAuthProxy 1.1.1 and earlier allows remote attackers to enter VNC sessions. VNCServerAuthenticator advertises the RFB “None” security type and marks clients authenticated when they select it, skipping the password challenge. The proxy must be accepting connections for the target VNC server; default-disabled client IP verification permits session access or displacement of a legitimate user.

CVSS severity9.8
Critical
EPSS probability2.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in VNCServerAuthenticator in OSU Open Source Lab VNCAuthProxy 1.1.1 and earlier allows remote attackers to enter VNC sessions. VNCServerAuthenticator advertises the RFB “None” security type and marks clients authenticated when they select it, skipping the password challenge. The proxy must be accepting connections for the target VNC server; default-disabled client IP verification permits session access or displacement of a legitimate user.

The record

CVE
CVE-2022-36436
Published
Sep 14, 2022
Updated
Aug 3, 2024
Vendor
OSU Open Source Lab
Product
VNCAuthProxy
Classifications
CWE-287, T1133
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OSU Open Source Lab · VNCAuthProxyversion=0 <=1.1.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1133External Remote Services

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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