CVE-2020-24356
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`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.
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 confidencecloudflared versions prior to 2020.8.1 running on Windows systems contain a local privilege escalation vulnerability. The application searches for configuration files in a manner that allows a local attacker with lower privileges to place or modify config files that will be executed with elevated (privileged) user context, achieving code execution as a privileged user.
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< 2020.8.1CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify cloudflared is installed on the Windows hostOpen Command Prompt or PowerShell and run: where cloudflared or check C:\Program Files\cloudflared or C:\Program Files (x86)\cloudflared directories for the executableAffected if cloudflared.exe is found on the system
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Determine the installed cloudflared versionRun: cloudflared --version to display the version numberAffected if Version displayed is earlier than 2020.8.1 (for example, 2020.7.3, 2020.6.0, etc.)
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Confirm the operating system is WindowsRun: systeminfo | findstr /B /C:"OS Name" or check the system propertiesAffected if The host operating system is Windows (the vulnerability only affects Windows systems)
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Identify configuration file search locationsRun cloudflared with verbose logging or inspect common config paths such as the directory where cloudflared.exe resides, user profile folders, or working directoryAffected if Configuration files can be placed in directories where lower-privileged users have write access that cloudflared may read from with elevated privileges
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Check file system permissions on config directoriesUse icacls or File Explorer security properties to verify write permissions on directories where cloudflared searches for config filesAffected if Lower-privileged users have write access to directories that cloudflared reads config from while running with elevated privileges
The environment is affected if cloudflared version 2020.8.1 or earlier is installed on a Windows system and configuration file directories are writable by lower-privileged users.
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 data2020.8.1
Upgrade cloudflared to version 2020.8.1 or later. Until upgraded, restrict write access to configuration file directories and ensure cloudflared does not run with unnecessary elevated privileges.
- Consultation4.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-24356 — 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-2020-24356 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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