CVE-2021-20037
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 · uneditedSonicWall Global VPN Client 4.10.5 installer (32-bit and 64-bit) incorrect default file permission vulnerability leads to privilege escalation which potentially allows command execution in the host operating system. This vulnerability impacts GVC 4.10.5 installer and earlier.
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 confidenceSonicWall Global VPN Client 4.10.5 installer (32-bit and 64-bit) creates files with overly permissive default ACLs, allowing unprivileged local users to modify executable files or configurations. This incorrect file permission enables privilege escalation to execute commands with elevated 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<= 4.10.5CVSS 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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Check if SonicWall Global VPN Client is installedLook for the application in the system registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall or check for the presence of SonicWall client files in Program Files or Program Files (x86) directoriesAffected if The software is present on the system and was installed with version 4.10.5 or earlier
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Identify the installed version of SonicWall Global VPN ClientOpen the Windows Registry and navigate to HKLM\SOFTWARE\SonicWall\Global VPN Client\Version, or right-click the client executable and view its Properties to find the File VersionAffected if The installed version is 4.10.5 or any version lower than 4.10.5
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Examine file permissions on the SonicWall installation directoryRight-click the SonicWall Global VPN Client installation folder in Program Files, select Properties, go to the Security tab, and review the permissions for Users andAuthenticated Users groupsAffected if Users or Authenticated Users have Write or Modify permissions to folders containing executable files (.exe) or configuration files (.xml, .ini, .conf)
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Verify executable files are modifiable by non-privileged usersOpen a command prompt as a standard (non-admin) user, navigate to the SonicWall installation directory, and attempt to delete or modify an executable file such as the client launcher or a .dll fileAffected if Standard users can successfully modify, delete, or replace executable files in the SonicWall installation directory
A user is affected if SonicWall Global VPN Client version 4.10.5 or lower is installed and non-privileged users have write access to executable or configuration files in the installation directory.
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 dataUpgrade to a patched version of SonicWall Global VPN Client (beyond 4.10.5) or apply vendor-provided security updates to remediate the improper file permissions.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-20037 — 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-2021-20037 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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