dbcve.org
UltravncApplication · Uvnc

CVE-2019-8280

CRITICAL · 9.8 CVSS v3.0 Published 2019-03-08
Fix available
A fix is available. Upgrade to 1.2.2.3 or later.
See remediation →
100/100
Remediation priority · Urgent
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 1203 has out-of-bounds access vulnerability in VNC client inside RAW decoder, which can potentially result code execution. This attack appear to be exploitable via network connectivity. This vulnerability has been fixed in revision 1204.

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 1203 contains an out-of-bounds access vulnerability in the VNC client's RAW decoder component. This memory corruption flaw is exploitable via network connectivity (VNC protocol) and can potentially allow remote code execution. The vulnerability was patched in revision 1204.

MitigationUpgrade UltraVNC to revision 1204 or later. If immediate patching is not feasible, restrict network access to trusted VNC servers only to reduce attack surface.

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

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
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Confirm UltraVNC client is installed
    Search for the UltraVNC executable (vncviewer.exe) in common installation directories such as C:\Program Files\UltraVNC or C:\Program Files (x86)\UltraVNC, or check Add/Remove Programs in Windows Control Panel
    Affected if UltraVNC is found on the system
  2. Identify the installed UltraVNC version
    Right-click vncviewer.exe, select Properties, then view the Details tab for the File Version, or run the client and check Help > About UltraVNC
    Affected if Version is below 1.2.2.3 or the revision number is 1203 or earlier
  3. Verify the RAW decoder is in use
    The RAW decoder is the default encoding format for VNC connections. When connecting to any VNC server using UltraVNC, the client negotiates encoding with the server - if RAW is negotiated or used as a fallback, this decoder is active
    Affected if The client successfully connects to a VNC server using RAW encoding (the default encoding for most VNC connections)
  4. Confirm vulnerability applicability
    Cross-reference the installed version from step 2 against the affected range: any version less than 1.2.2.3 (or revision 1203) is vulnerable when the RAW decoder is active during VNC connections
    Affected if Installed version is less than 1.2.2.3 and the client is used to connect to VNC servers

You are affected if UltraVNC version 1.2.2.3 or earlier (revision 1203 or below) is installed and used to connect to VNC servers, as the RAW decoder vulnerability triggers during normal client-server communication.

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.

dbcve · scoped
Upgrade available Upgrade to 1.2.2.3 or later
Fixed in 1.2.2.3
Interim mitigation

Upgrade UltraVNC to revision 1204 or later. If immediate patching is not feasible, restrict network access to trusted VNC servers only to reduce attack surface.

Recommended fix High confidence

UltraVNC 1.2.2.4 (revision 1204)

  1. Download UltraVNC version 1.2.2.4 (revision 1204) or later from the official UltraVNC website or trusted distribution source
  2. Uninstall the currently installed vulnerable version of UltraVNC
  3. Install the downloaded fixed version (1.2.2.4 or higher)
  4. Verify the installed version matches or exceeds the fixed release

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Ultravnc Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-8280 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2019-8280 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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