Octopus ServerApplication · Octopus

CVE-2018-18850

HIGH · 8.8 CVSS v3.0 Published 2018-10-31
Fix available
A fix is available. Upgrade to 2018.9.1 or later.
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
In Octopus Deploy 2018.8.0 through 2018.9.x before 2018.9.1, an authenticated user with permission to modify deployment processes could upload a maliciously crafted YAML configuration, potentially allowing for remote execution of arbitrary code, running in the same context as the Octopus Server (for self-hosted installations by default, SYSTEM).

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 YAML deserialization vulnerability in Octopus Deploy versions 2018.8.0 through 2018.9.x before 2018.9.1 allows authenticated users with deployment process modification permissions to upload malicious YAML configurations that can trigger remote code execution. The injected code runs in the context of the Octopus Server process, which by default operates as SYSTEM on self-hosted installations.

MitigationUpgrade Octopus Deploy to version 2018.9.1 or later. In the interim, restrict or audit deployment process modification permissions to only highly trusted administrators.

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
Octopus ServerApplication
Affected:>= 2018.8.0, <= 2018.8.12>= 2018.9.0, < 2018.9.1

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:3.0/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 installed Octopus Server version
    Locate the Octopus Server installation and check its version number, typically visible in the Octopus web portal header or in the installation directory's version info
    Affected if The installed version falls within 2018.8.0 to 2018.8.12, or 2018.9.0 to 2018.9.0 (the version shown is less than 2018.9.1)
  2. Confirm deployment process feature is accessible
    Verify that the Octopus Deploy deployment process functionality is enabled and accessible in the installation; this feature is present in standard Octopus Server installations
    Affected if The deployment process module is available and active in the Octopus Server instance
  3. Review user roles with deployment process modification permissions
    Access the Octopus Administrator interface and examine the roles and permissions configuration to identify which users or teams have the ability to modify deployment processes
    Affected if Any user account other than fully trusted administrators has been granted permissions to modify deployment processes
  4. Check for unauthorized or suspicious deployment process configurations
    Audit the deployment process configurations stored in Octopus for any unexpected or malicious YAML content, particularly in step templates or variable sets that accept YAML input
    Affected if Any deployment process contains YAML configurations that were not created by known, trusted administrators
  5. Verify Octopus Server process identity
    Inspect the Windows Task Manager or service configuration to confirm the account context under which the Octopus Server service runs
    Affected if The Octopus Server service runs as SYSTEM or a high-privilege account, which would allow injected code to execute with elevated privileges

Your environment is affected if the Octopus Server version is 2018.8.0 through 2018.8.12 or 2018.9.0 through 2018.9.0, and users with deployment process modification permissions exist in the system.

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
Upgrade available Upgrade to 2018.9.1 or later
Fixed in 2018.9.1
Interim mitigation

Upgrade Octopus Deploy to version 2018.9.1 or later. In the interim, restrict or audit deployment process modification permissions to only highly trusted administrators.

Fix this in Octopus Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-18850 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-18850 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