CVE-2020-22845
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 · uneditedA buffer overflow in Mikrotik RouterOS 6.47 allows unauthenticated attackers to cause a denial of service (DOS) via crafted FTP requests.
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 confidenceBuffer overflow vulnerability in Mikrotik RouterOS 6.47 FTP service allows unauthenticated remote attackers to crash the router via specially crafted FTP requests, resulting in denial of service.
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= 6.47CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Identify RouterOS versionRun /system resource print in RouterOS CLI or check the web interface under System > Resources. Look for the 'version' field in the output.Affected if Version shows exactly 6.47 or falls within the affected 6.47 release line
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Verify FTP service is enabledRun /ip service print in RouterOS CLI. Check if the 'ftp' service has an 'address' value other than 0.0.0.0/0 or shows as enabled in the web interface under IP > Services.Affected if FTP service is listed as enabled and accessible (address is not restricted to localhost/internal networks only)
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Confirm FTP port is listening and exposedRun /ip firewall filter print in RouterOS CLI and inspect rules on chain input that reference port 21 or the FTP service. Alternatively, run netstat -an | grep :21 from the CLI to confirm port 21 is listening.Affected if Port 21 is listening and firewall rules allow external/any source access to the FTP service
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Check network exposure of FTPReview firewall rules in /ip firewall filter for any input-chain rules that allow dst-port=21 from external addresses. Run /ip address print to identify thewan-facing IP addresses.Affected if FTP service can be reached fromwan or untrusted network segments (rules permit any or broad external ranges to port 21)
A user is affected if they run Mikrotik RouterOS version 6.47 (or the affected 6.47 release) with the FTP service enabled and exposed to network locations where an attacker could send malicious FTP requests.
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 RouterOS to a patched version beyond 6.47; if immediate patching is not feasible, disable or restrict FTP access at network boundaries and implement rate limiting on port 21.
- Consultation2.0 h
- Implementation2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-22845 — 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-2020-22845 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
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