CVE-2001-1422
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 · uneditedWinVNC 3.3.3 and earlier generates the same challenge string for multiple connections, which allows remote attackers to bypass VNC authentication by sniffing the challenge and response of other users.
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 confidenceWinVNC 3.3.3 and earlier uses a static challenge in the VNC authentication protocol instead of generating a unique random challenge per connection. An attacker who intercepts (sniffs) a valid challenge-response pair can replay it to authenticate successfully, bypassing the intended password protection.
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<= 3.3.3CVSS 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
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:P/A:P
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 if WinVNC is installedOpen Windows Task Manager and look for 'winvnc.exe' in the Processes tab, or check Add/Remove Programs for WinVNC entries. Also check for WinVNC service in Services (services.msc).Affected if WinVNC process or service is found running on the system
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Identify WinVNC versionRight-click on winvnc.exe in Task Manager and select Properties, or check the version in the program's installation directory. You can also run 'winvnc.exe -version' if supported, or view version info in the executable's file properties.Affected if Version is 3.3.3 or earlier (any version <= 3.3.3)
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Confirm VNC authentication is enabledCheck if VNC authentication is configured by examining the WinVNC settings or registry keys under HKLM\SOFTWARE\ORL\WinVNC3 (or HKCU\Software\ORL\WinVNC3) for Password and Security settings.Affected if VNC authentication is enabled (password protection is configured)
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Verify network exposureUse netstat or a network scanning tool to confirm port 5900 (or custom VNC port) is listening and accessible from network. Run 'netstat -an | findstr 5900' to check listening ports.Affected if VNC port is listening and accessible from network (not localhost only)
If WinVNC version 3.3.3 or earlier is running with VNC authentication enabled and exposed to the network, the system is vulnerable to replay attack due to static challenge implementation.
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.
From vendor dataUpgrade to a version of WinVNC that generates unique random challenges per connection, or migrate to a maintained VNC implementation with proper challenge-response implementation.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA0.5 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2001-1422 — 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-2001-1422 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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- 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