CVE-2020-7881
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 · uneditedThe vulnerability function is enabled when the streamer service related to the AfreecaTV communicated through web socket using 21201 port. A stack-based buffer overflow leading to remote code execution was discovered in strcpy() operate by "FanTicket" field. It is because of stored data without validation of length.
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 confidenceA stack-based buffer overflow vulnerability exists in the AfreecaTV streamer service (WebSocket port 21201). The strcpy() function copies the 'FanTicket' field into a fixed-size stack buffer without validating input length, allowing an attacker to overflow the buffer and achieve remote code execution.
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= 1.0.0.1CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 if AfreecaTV streamer software is installedSearch for Afreecatv installation directories or check installed programs list. Common paths may include C:\Program Files\Afreecatv or %APPDATA%\Afreecatv on Windows, or /Applications/Afreecatv on macOSAffected if AfreecaTV streamer software is found on the system
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Identify the installed AfreecaTV versionLocate the main executable (typically afreecatv.exe or similar) and use file properties or version inquiry commands (such as 'ver' command on Windows or file version info) to determine the exact version numberAffected if The installed version matches 1.0.0.1 exactly (or falls within the affected range if additional versions are later identified)
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Verify the streamer service is running and port 21201 is listeningCheck network connections using netstat or similar tool: 'netstat -an | grep 21201' or 'netstat -ano | findstr :21201' on Windows. Confirm the service is bound and listening on this WebSocket portAffected if Port 21201 is in LISTENING state and bound to the AfreecaTV streamer service
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Confirm the FanTicket feature is accessibleInspect the application configuration or logs to verify the FanTicket functionality is enabled and reachable through the WebSocket service on port 21201Affected if FanTicket feature is enabled and the WebSocket endpoint on port 21201 is accessible from the system
The system is affected if AfreecaTV version 1.0.0.1 is installed, the streamer service is running with port 21201 listening, and the FanTicket WebSocket endpoint is accessible.
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 dataImplement strict length validation on the FanTicket field before copying, and replace strcpy() with safe string functions (strncpy, strlcpy, or memcpy with explicit bounds checking) that enforce buffer limits.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-7881 — 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-2020-7881 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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- Version or environment caveats, and links to real fixes
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