Dir 620 FirmwareOperating system · Dlink

CVE-2018-6210

CRITICAL · 9.8 CVSS v3.1 Published 2018-06-19
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
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
D-Link DIR-620 devices, with a certain Rostelekom variant of firmware 1.0.37, have a hardcoded rostel account, which makes it easier for remote attackers to obtain access via a TELNET session.

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

D-Link DIR-620 routers running a Rostelekcom-specific firmware variant (version 1.0.37) contain a hardcoded backdoor account ('rostel') with a static password. This account is accessible via remote TELNET, allowing unauthenticated attackers to gain full administrative access to the router.

MitigationApply vendor firmware patch if available; otherwise disable remote TELNET access via router administration panel, implement network segmentation to restrict TELNET exposure, or replace affected devices with supported hardware.

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
Dir 620 FirmwareOperating system
Affected:= 1.0.37

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. Identify the router model
    Access the router web administration panel or check the device label to confirm the model is D-Link DIR-620
    Affected if The device is not a D-Link DIR-620 model, then it is not affected by this specific CVE
  2. Check the firmware version
    Log into the router web interface and navigate to the Status or System Information page to view the firmware version, or use the command 'cat /proc/version' or 'cat /etc/firmware_version' via TELNET/SSH if accessible
    Affected if The firmware version is exactly 1.0.37 (Rostelekcom variant), indicating the affected version
  3. Verify if remote TELNET is enabled
    Check the router web administration panel under Security or Access Control settings for TELNET service status, or attempt to connect to the router's public IP on port 23 (TELNET) from an external network
    Affected if Remote TELNET access is enabled and exposed to the network, allowing potential exploitation of the backdoor
  4. Confirm the rostel backdoor account exists
    Attempt to login via TELNET using the username 'rostel' with the static password, or inspect the router's /etc/passwd or /etc/shadow file via TELNET/SSH if administrative access is already obtained
    Affected if The 'rostel' account exists and grants full administrative access, confirming the vulnerability is exploitable

The device is affected if it is a D-Link DIR-620 router running Rostelekcom firmware version 1.0.37 with remote TELNET enabled, allowing authentication with the hardcoded 'rostel' backdoor account.

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

Apply vendor firmware patch if available; otherwise disable remote TELNET access via router administration panel, implement network segmentation to restrict TELNET exposure, or replace affected devices with supported hardware.

Fix this in Dir 620 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2018-6210 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
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