CVE-2020-5759
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 · uneditedGrandstream UCM6200 series firmware version 1.0.20.23 and below is vulnerable to OS command injection via SSH. An authenticated remote attacker can execute commands as the root user by issuing a specially crafted "unset" command.
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 confidenceOS command injection vulnerability in Grandstream UCM6200 series devices allows authenticated remote attackers to execute arbitrary commands as root via specially crafted 'unset' commands sent over SSH.
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<= 1.0.20.23<= 1.0.20.23<= 1.0.20.23CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Confirm device modelIdentify the Grandstream UCM device model via web interface status page, device label, or SSH prompt. Look for UCM6202, UCM6204, or UCM6208.Affected if Device is NOT one of UCM6202, UCM6204, or UCM6208 (not affected)
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Check firmware versionAccess the device web interface and navigate to System Settings > System Info, or run 'gs_cgi --get_system_info' via SSH or serial console to retrieve the firmware version number.Affected if Firmware version is 1.0.20.23 or lower (vulnerable)
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Verify SSH service statusCheck if the SSH service is enabled and listening. From the web interface, go to Security Settings > SSH Settings, or run 'netstat -tlnp | grep 22' to confirm port 22 is open.Affected if SSH is enabled and accessible from untrusted networks (exposed)
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Review SSH access controlsInspect the device firewall or access list settings to determine if SSH is restricted to specific trusted IP addresses. Check under Security Settings > SSH Settings or firewall rules.Affected if SSH is open to unrestricted network access (higher exposure)
Device is affected if it is a UCM6202, UCM6204, or UCM6208 running firmware version 1.0.20.23 or lower with SSH service enabled and 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 dataUpgrade firmware to version above 1.0.20.23; if upgrade is not feasible immediately, restrict SSH access to trusted IP addresses using firewall rules.
- Consultation3.0 h
- Implementation4.0 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 $2,880.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5759 — 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-2020-5759 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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