Ucm6202 FirmwareOperating system · Grandstream

CVE-2020-5758

HIGH · 8.8 CVSS v3.1 Published 2020-07-17
Fix available
A fix is available. Upgrade to after 1.0.20.23 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
Grandstream UCM6200 series firmware version 1.0.20.23 and below is vulnerable to OS command injection via HTTP. An authenticated remote attacker can execute commands as the root user by sending a crafted HTTP GET to the UCM's "Old" HTTPS API.

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 confidence

The Grandstream UCM6200 series IP PBX firmware versions 1.0.20.23 and below contains an OS command injection vulnerability in the 'Old' HTTPS API endpoint. An authenticated remote attacker can send specially crafted HTTP GET requests to execute arbitrary operating system commands with root privileges.

MitigationUpgrade Grandstream UCM6200 firmware to version 1.0.20.24 or higher. If immediate patching is not feasible, restrict network access to the vulnerable 'Old' HTTPS API endpoint using firewall rules or disable the endpoint if functionality permits.

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
Ucm6202 FirmwareOperating system
Affected:<= 1.0.20.23
Ucm6204 FirmwareOperating system
Affected:<= 1.0.20.23
Ucm6208 FirmwareOperating system
Affected:<= 1.0.20.23

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the firmware version
    Log into the UCM6200 web interface and navigate to System Settings > Upgrade, or access the device via SSH and run 'show ver' or check /proc/version to retrieve the installed firmware version
    Affected if The firmware version is 1.0.20.23 or any version lower than 1.0.20.23
  2. Confirm the device model
    Check the device label or access the web interface dashboard to confirm the exact model (UCM6202, UCM6204, or UCM6208)
    Affected if The device is a UCM6202, UCM6204, or UCM6208 running vulnerable firmware
  3. Verify the Old HTTPS API endpoint is accessible
    Attempt to access the /api endpoint via HTTPS from an authorized network location, or check the web interface under Application > API Settings to see if the legacy/Old API is enabled
    Affected if The Old HTTPS API endpoint is enabled and reachable over the network
  4. Check remote access configuration
    Navigate to System Settings > Remote Access in the web interface, or inspect firewall rules via the CLI with 'iptables -L' to determine if the device accepts remote authenticated requests
    Affected if Remote management or API access is permitted from untrusted networks

The environment is affected if the device is a UCM6202, UCM6204, or UCM6208 running firmware version 1.0.20.23 or below AND the Old HTTPS API endpoint is enabled and accessible to the attacker.

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
Upgrade available Upgrade to a release after 1.0.20.23
Interim mitigation

Upgrade Grandstream UCM6200 firmware to version 1.0.20.24 or higher. If immediate patching is not feasible, restrict network access to the vulnerable 'Old' HTTPS API endpoint using firewall rules or disable the endpoint if functionality permits.

Fix this in Ucm6202 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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Scan for this in your stack

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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-2020-5758 in production — separate from our analysis above.

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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
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  • No spam, self-promotion, credentials, or personal data