V1600d FirmwareOperating system · Vsolcn

CVE-2020-29378

HIGH · 8.8 CVSS v3.1 Published 2020-11-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
An issue was discovered on V-SOL V1600D V2.03.69 and V2.03.57, V1600D4L V1.01.49, V1600D-MINI V1.01.48, V1600G1 V2.0.7 and V1.9.7, and V1600G2 V1.1.4 OLT devices. It is possible to elevate the privilege of a CLI user (to full administrative access) by using the password !j@l#y$z%x6x7q8c9z) for the enable 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 confidence

A hardcoded backdoor password (!j@l#y$z%x6x7q8c9z) in V-SOL OLT devices allows any authenticated CLI user to escalate privileges to full administrative access via the 'enable' command. This bypasses normal authorization controls and provides complete device control.

MitigationApply vendor firmware updates when available; immediately change all default credentials and audit device access logs for unauthorized use of the enable command with this password.

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
V1600d FirmwareOperating system
Affected:= 2.03.57= 2.03.69
V1600d4l FirmwareOperating system
Affected:= 1.01.49
V1600d Mini FirmwareOperating system
Affected:= 1.01.48
V1600g1 FirmwareOperating system
Affected:= 1.9.7= 2.0.7
V1600g2 FirmwareOperating system
Affected:= 1.1.4

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 device model
    Access the device CLI and run 'show version' or check the boot logs to confirm the exact V-SOL OLT model (V1600d, V1600d4l, V1600d Mini, V1600g1, or V1600g2)
    Affected if The device model is one of the listed affected models
  2. Check the firmware version
    Run 'show version' or 'show firmware' in the CLI to retrieve the installed firmware version
    Affected if The firmware version matches exactly 2.03.57, 2.03.69, 1.01.49, 1.01.48, 1.9.7, 2.0.7, or 1.1.4 for the respective model
  3. Test the backdoor password
    Log into the CLI with any valid user account, then run 'enable' and try the password '!j@l#y$z%x6x7q8c9z' when prompted
    Affected if The password is accepted and grants full administrative access without proper authorization
  4. Audit enable command usage in logs
    Review device logs using 'show log' or check syslog exports for entries containing the 'enable' command combined with the backdoor password pattern
    Affected if Logs show 'enable' command usage that succeeded using the hardcoded password instead of a proper admin password

The device is affected if it is a V-SOL V1600 series OLT running one of the specific firmware versions listed and the backdoor password grants administrative access.

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 updates when available; immediately change all default credentials and audit device access logs for unauthorized use of the enable command with this password.

Fix this in V1600d Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2020-29378 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
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  • Version or environment caveats, and links to real fixes
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