CVE-2021-42133
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 · uneditedAn exposed dangerous function vulnerability exists in Ivanti Avalanche before 6.3.3 allows an attacker with access to the Inforail Service to perform an arbitrary file write.
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 · moderate confidenceIvanti Avalanche versions before 6.3.3 contain an exposed dangerous function in the Inforail Service that allows an authenticated or local attacker to write arbitrary files to the filesystem, potentially leading to code execution or system compromise.
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< 6.3.3CVSS 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
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/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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Identify if Ivanti Avalanche is installedCheck for Ivanti Avalanche installation directories, services, or registry entries on the system. Common locations include C:\Program Files\Avalanche or C:\Inetpub\Avalanche on Windows systems.Affected if Ivanti Avalanche software is present on the system
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Determine the installed versionLocate the version information in the installation directory, check the service properties, or use command-line tools such as 'wmic product get name,version' or 'reg query' to query installed software details.Affected if The installed version is lower than 6.3.3
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Verify the Inforail Service statusCheck if the Inforail Service is running by opening Services (services.msc) or using 'sc query inforail' or 'net start' commands to list running services.Affected if The Inforail Service is installed and running on the system
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Assess network exposure of the Inforail ServiceReview network configuration, firewall rules, and service bindings to determine if the Inforail Service is accessible over the network. Check for open ports associated with the service using 'netstat -an' or port scanning tools.Affected if The Inforail Service is exposed to network access without proper authentication controls
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Review authentication configurationExamine the Inforail Service configuration files, authentication settings, and access control lists to determine if anonymous or low-privileged access is permitted.Affected if The service allows authenticated users or local users to invoke the dangerous file write function
A system is affected if Ivanti Avalanche version is below 6.3.3 and the Inforail Service is running and accessible to authenticated or local users who could invoke the exposed file writing function.
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 · scoped6.3.3
Upgrade Ivanti Avalanche to version 6.3.3 or later to address the exposed dangerous function. If immediate patching is not possible, restrict access to the Inforail Service and monitor for unauthorized file write attempts.
Ivanti Avalanche 6.3.3
- Obtain Ivanti Avalanche version 6.3.3 or later from the official Ivanti download portal or support channels
- Review the Ivanti Avalanche upgrade documentation for your current version
- Back up your current Avalanche configuration and database before proceeding with the upgrade
- Install Avalanche 6.3.3 or later following the official upgrade procedures
- Verify the upgrade was successful by checking the Avalanche version in the admin console
- Confirm the Inforail Service is properly configured and restricted to authorized personnel only
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-42133 — 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-2021-42133 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
- No spam, self-promotion, credentials, or personal data