Classic Buffer OverflowWeakness · CWE-120

CVE-2021-47798

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit 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
NoteBurner 2.35 contains a buffer overflow vulnerability in the license code input field that allows attackers to crash the application. Attackers can generate a 6000-byte payload and paste it into the 'Name' and 'Code' fields to trigger an application crash.

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 confidence

NoteBurner 2.35 contains a buffer overflow vulnerability in the license code input fields where a 6000-byte payload pasted into the 'Name' and 'Code' fields overwrites adjacent memory and causes application crash. The lack of proper input length validation on these fields allows arbitrary data to exceed buffer boundaries.

MitigationImplement strict input length validation and bounds checking on all user input fields, particularly the license 'Name' and 'Code' fields, to ensure data does not exceed allocated buffer sizes.

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

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:3.1/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. Check NoteBurner version
    Open NoteBurner and navigate to Help > About, or right-click the application and select Properties > Details to view the installed version number
    Affected if The installed version is 2.35 exactly, or any version between the affected release and the current version that has not been patched
  2. Verify license input feature exists
    Launch NoteBurner and locate the license activation window typically found under Help > Enter License Code or a similar license registration interface
    Affected if The license Name and Code input fields are present and accessible in the application
  3. Confirm lack of input length enforcement
    Attempt to paste or type an extremely long string (e.g., 6000+ characters) into the license Name and Code fields to observe if the application accepts input exceeding normal lengths
    Affected if The application accepts input well beyond typical license code lengths without truncation or validation errors, indicating missing bounds checking
  4. Check for crash behavior
    After pasting the large payload into the Name and Code fields and attempting to submit/activate the license, observe if the application crashes, freezes, or exhibits unexpected behavior
    Affected if The application crashes or becomes unstable when processing oversized input in these fields, confirming the buffer overflow condition

A user is affected if NoteBurner version 2.35 (or an unpatched version) is installed and the license Name/Code fields accept oversized input that causes a crash or memory corruption.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input length validation and bounds checking on all user input fields, particularly the license 'Name' and 'Code' fields, to ensure data does not exceed allocated buffer sizes.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-47798 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-47798 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
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