Versa Operating SystemOperating system · Versa Networks

CVE-2018-16499

MEDIUM · 5.9 CVSS v3.1 Published 2021-05-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
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
In VOS compromised, an attacker at network endpoints can possibly view communications between an unsuspecting user and the service using man-in-the-middle attacks. Usage of unapproved SSH encryption protocols or cipher suites also violates the Data Protection TSR (Technical Security Requirements).

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 · moderate confidence

VOS uses weak or unapproved SSH encryption protocols and cipher suites that are susceptible to man-in-the-middle attacks, allowing an attacker at network endpoints to intercept and view communications between users and the service. This violates Data Protection TSR requirements for approved cryptographic protections.

MitigationUpdate SSH daemon configuration on VOS systems to use only FIPS 140-2 validated or organizationally approved cipher suites and key exchange algorithms, then restart SSH services and verify connectivity.

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
Versa Operating SystemOperating system
Affected:all versions

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
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 checks

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

  1. Access SSH daemon configuration
    Log into the VOS CLI and examine the SSH daemon configuration file, typically located at /etc/ssh/sshd_config or accessed via 'show system services ssh'
    Affected if Configuration file cannot be accessed or does not exist
  2. Check configured SSH cipher suites
    Locate the 'Ciphers' directive in the SSH configuration and list all allowed cipher algorithms
    Affected if Weak or legacy ciphers are present (e.g., 3des-cbc, aes128-cbc, aes192-cbc, aes256-cbc, blowfish-cbc, cast128-cbc)
  3. Check configured key exchange algorithms
    Locate the 'KexAlgorithms' or 'KeyExchanges' directive and list all allowed key exchange methods
    Affected if Weak key exchange algorithms are present (e.g., diffie-hellman-group1-sha1, diffie-hellman-group14-sha1)
  4. Check configured MAC algorithms
    Locate the 'MACs' directive and list all allowed message authentication code algorithms
    Affected if Weak MAC algorithms are present (e.g., hmac-md5, hmac-md5-96, hmac-sha1, hmac-sha1-96)
  5. Verify against approved cryptographic standards
    Compare all configured SSH ciphers, key exchange algorithms, and MACs against FIPS 140-2 validated or organizationally approved lists
    Affected if Any weak, deprecated, or non-approved cryptographic primitives are configured

The environment is affected if the VOS SSH daemon configuration contains any weak cipher suites, key exchange algorithms, or MAC algorithms that are not FIPS 140-2 validated or organizationally approved.

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

Update SSH daemon configuration on VOS systems to use only FIPS 140-2 validated or organizationally approved cipher suites and key exchange algorithms, then restart SSH services and verify connectivity.

Fix this in Versa Operating System Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,440
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Scan for this in your stack

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dbcve dependency scanner

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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-2018-16499 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data