UltravncApplication · Uvnc

CVE-2019-8269

HIGH · 7.5 CVSS v3.1 Published 2019-03-08
Fix available
A fix is available. Upgrade to 1.2.2.3 / 4.8 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
UltraVNC revision 1206 has stack-based Buffer overflow vulnerability in VNC client code inside FileTransfer module, which leads to a denial of service (DoS) condition. This attack appear to be exploitable via network connectivity. This vulnerability has been fixed in revision 1207.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

UltraVNC revision 1206 contains a stack-based buffer overflow vulnerability in the VNC client code within the FileTransfer module. This flaw is exploitable remotely via network connectivity and can be leveraged to cause a denial of service condition.

MitigationUpgrade UltraVNC to revision 1207 or later to address the vulnerability, as no workarounds are described in the available documentation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
UltravncApplication
Affected:< 1.2.2.3
Sinumerik Access Mymachine\/p2pApplication
Affected:< 4.8
Sinumerik Pcu Base Win10 Software\/ipcApplication
Affected:< 14.00
Sinumerik Pcu Base Win7 Software\/ipcApplication
Affected:<= 12.01

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify UltraVNC installation
    Open Windows Control Panel > Programs and Features, or run 'wmic product get name,version' to list installed software and locate UltraVNC
    Affected if UltraVNC version is listed as less than 1.2.2.3
  2. Check UltraVNC executable version
    Right-click the UltraVNC executable (typically in C:\Program Files\UltraVNC or C:\Program Files (x86)\UltraVNC), select Properties, and view the File Version on the Details tab
    Affected if File version shown is below 1.2.2.3 or shows revision 1206 or earlier
  3. Identify Siemens Sinumerik installations
    Check for Siemens Sinumerik software installations on the system via Windows Programs and Features, looking for 'Sinumerik Access Mymachine', 'Sinumerik Pcu Base Win10 Software', or 'Sinumerik Pcu Base Win7 Software'
    Affected if Any listed Siemens Sinumerik software version is below 4.8, 14.00, or 12.01 respectively
  4. Confirm FileTransfer usage context
    The vulnerability exists in the VNC client FileTransfer module. If UltraVNC is configured as a viewer used to connect to remote VNC servers, the FileTransfer feature may be invoked during connections
    Affected if UltraVNC viewer is used to connect to untrusted VNC servers and FileTransfer feature is enabled in the connection settings

Your environment is affected if UltraVNC revision 1206 or any version below 1.2.2.3 is installed, or if any Siemens Sinumerik software listed is below the specified version thresholds.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 1.2.2.3 / 4.8 / 14.00 or later
Fixed in 1.2.2.34.814.00
Interim mitigation

Upgrade UltraVNC to revision 1207 or later to address the vulnerability, as no workarounds are described in the available documentation.

Fix this in Ultravnc Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,190
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-8269 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data