CVE-2020-24359
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 · uneditedHashiCorp vault-ssh-helper up to and including version 0.1.6 incorrectly accepted Vault-issued SSH OTPs for the subnet in which a host's network interface was located, rather than the specific IP address assigned to that interface. Fixed in 0.2.0.
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 confidencevault-ssh-helper versions 0.1.6 and earlier had a flaw in its OTP validation logic: it accepted SSH one-time passwords for any IP within the same subnet as the target host's network interface, rather than validating only against the specific IP address assigned to that interface. This allowed attackers on the same subnet to authenticate to any machine in that subnet using a single compromised OTP.
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< 0.2.0CVSS 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
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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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Verify vault-ssh-helper installationRun 'which vault-ssh-helper' or look for the binary in common paths like /usr/local/bin/vault-ssh-helper, /usr/bin/vault-ssh-helper, or check your configuration management tool for installed packages.Affected if vault-ssh-helper binary is not found on the system, meaning the product is not installed.
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Determine installed versionRun 'vault-ssh-helper -version' or 'vault-ssh-helper --version' to obtain the version number.Affected if The reported version is 0.1.6 or earlier, or any version less than 0.2.0.
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Locate configuration fileCheck for /etc/vault-ssh-helper.d/config.hcl or the configuration file path specified in your SSH authentication setup.Affected if A configuration file exists and vault-ssh-helper version is below 0.2.0.
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Check for active OTP authentication logsReview authentication logs (/var/log/auth.log, /var/log/secure, or systemd journal for vault-ssh-helper) for OTP authentication events.Affected if OTP authentications are occurring and the vault-ssh-helper version is below 0.2.0.
You are affected if vault-ssh-helper is installed with any version prior to 0.2.0 and OTP authentication is in use, as the flawed subnet-based IP validation logic is present.
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 data0.2.0
Upgrade vault-ssh-helper to version 0.2.0 or later, which correctly validates OTPs against the specific IP address rather than the subnet range.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-24359 — 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-2020-24359 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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