CVE-2018-6823
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 · uneditedIn the VPN client in Mailbutler Shimo before 4.1.5.1 on macOS, the com.feingeist.shimo.helper tool LaunchDaemon implements an unprotected XPC service that can be abused to execute scripts as root.
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 confidenceThe Shimo VPN client for macOS includes a LaunchDaemon helper tool (com.feingeist.shimo.helper) that implements an XPC service lacking proper authentication controls. This unprotected XPC endpoint allows any local user to send privileged messages to the service, enabling arbitrary script execution with root (SYSTEM) privileges.
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< 4.1.5.1CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Confirm Shimo VPN is installedRun: ls -la /Applications/ | grep -i shimo OR ls -la ~/Applications/ | grep -i shimoAffected if Shimo VPN client is found in Applications
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Determine installed Shimo versionRun: defaults read /Applications/Shimo.app/Contents/Info CFBundleVersion 2>/dev/null || mdls -name kCFBundleVersionKey /Applications/Shimo.appAffected if Version number returned is less than 4.1.5.1
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Check if vulnerable helper tool existsRun: ls -la /Library/PrivilegedHelperTools/ 2>/dev/null | grep -i shimoAffected if com.feingeist.shimo.helper binary exists in the privileged helper tools directory
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Verify helper LaunchDaemon configurationRun: ls -la /Library/LaunchDaemons/ 2>/dev/null | grep -i shimoAffected if com.feingeist.shimo.helper.plist exists in LaunchDaemons
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Check helper tool accessibilityRun: ls -la /Library/PrivilegedHelperTools/com.feingeist.shimo.helper 2>/dev/nullAffected if The helper binary exists and is readable/executable by standard users (world-readable permissions indicate the vulnerability is exploitable)
A user is affected if Shimo VPN client version is below 4.1.5.1 AND the com.feingeist.shimo.helper tool is installed and accessible to unprivileged local users, allowing arbitrary script execution with root privileges.
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.
dbcve · scoped4.1.5.1
Update Shimo VPN client to version 4.1.5.1 or later, which implements proper XPC service protection. Verify the helper tool is no longer accessible to unprivileged users after the update.
4.1.5.1 or later
- Upgrade Shimo VPN client to version 4.1.5.1 or later to resolve the unprotected XPC service vulnerability that allows privilege escalation to root
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-6823 — 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-2018-6823 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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