CVE-2020-29380
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 · uneditedAn 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. TELNET is offered by default but SSH is not always available. An attacker can intercept passwords sent in cleartext and conduct a man-in-the-middle attack on the management of the appliance.
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 confidenceV-SOL OLT devices have TELNET enabled by default, which transmits passwords and management traffic in cleartext. Since SSH is not consistently available across all firmware versions, attackers on the network path can intercept credentials and perform man-in-the-middle attacks on device management.
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= 2.03.57= 2.03.69= 1.01.49= 1.01.48= 1.9.7= 2.0.7= 1.1.4CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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 the device model and firmware versionAccess the OLT web interface or CLI and retrieve the device model (V1600d, V1600d4l, V1600d Mini, V1600g1, or V1600g2) and firmware version information from the system status or about pageAffected if The device is a V-SOL OLT model and the firmware version matches 2.03.57, 2.03.69, 1.01.49, 1.01.48, 1.9.7, 2.0.7, or 1.1.4 from the affected versions list
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Check if TELNET service is enabledLog into the device CLI or web interface and navigate to the network services or port configuration section. Look for TELNET server settings or port 23 configurationAffected if TELNET service is enabled and listening on the device (typically port 23)
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Verify if SSH management is availableCheck the device configuration for SSH (secure shell) options under management access settings. Attempt an SSH connection to the device on port 22 if availableAffected if SSH is not listed as an available option in the firmware, or SSH connectivity fails and TELNET is the only management protocol available
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Test for cleartext credential captureFrom a test workstation on the same network segment, use a packet capture tool (such as tcpdump or Wireshark) while authenticizing to the device via TELNET. Inspect the captured packets for plaintext username and password stringsAffected if TELNET authentication traffic contains readable username and password in plain text rather than encrypted data
A user is affected if they are running one of the listed V-SOL OLT firmware versions and TELNET is currently enabled as a management access method, with SSH unavailable or not consistently supported in that firmware version.
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 dataDisable TELNET and enable SSH for management access. If SSH is unavailable in the current firmware, upgrade to a version that supports SSH or implement VPN/out-of-band management for secure administrative access.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-29380 — 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-2020-29380 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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