CVE-2019-8264
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 · uneditedUltraVNC revision 1203 has out-of-bounds access vulnerability in VNC client inside Ultra2 decoder, which can potentially result in code execution. This attack appears 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 · moderate confidenceUltraVNC revision 1203 contains an out-of-bounds memory access vulnerability in the VNC client's Ultra2 decoder component. This flaw is exploitable remotely via network connectivity and can potentially allow an attacker to execute arbitrary code by connecting a vulnerable client to a malicious VNC server.
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< 1.2.2.3CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check installed UltraVNC versionOpen UltraVNC client (vncviewer.exe), go to Help > About, or right-click the tray icon and select 'About UltraVNC' to view the exact version numberAffected if The displayed version is earlier than 1.2.2.3 (for example, 1.2.2.2, 1.2.1.x, or older releases)
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Verify Ultra2 encoding supportOpen UltraVNC client settings (usually accessible via Options button or right-click tray icon > Options), look under 'Encoding' or 'Options' for the Ultra2 or 'Ultra' encoding settingAffected if Ultra2 encoding is enabled or listed as an available option in the client configuration
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Inspect client configuration fileLocate the UltraVNC configuration file (typically ultravnc.ini in the UltraVNC installation directory or user profile), search for parameters related to encoding or decoder settingsAffected if The configuration file contains entries enabling or preferring Ultra2 encoding for client connections
A user is affected if they are running UltraVNC client versions earlier than 1.2.2.3 and have used or intend to use the Ultra2 decoder to connect to remote VNC servers.
Generated from the published advisory. Verify against your own configuration.
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 · scoped1.2.2.3
Upgrade UltraVNC to revision 1204 or later. If immediate patching is not feasible, restrict network connectivity to untrusted VNC servers and disable automatic connections to remote desktops.
UltraVNC revision 1204 or version 1.2.2.3+
- 1. Identify the current UltraVNC version installed on the system
- 2. Navigate to the official UltraVNC download page or trusted distribution source
- 3. Download UltraVNC revision 1204 (or version 1.2.2.3 or later)
- 4. Close any running UltraVNC client or server instances
- 5. Install the updated version, replacing the vulnerable installation
- 6. Verify the installed version matches the fixed release (1.2.2.3 or later)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,912.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-8264 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-8264 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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