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Serv UApplication · Solarwinds

CVE-2021-35245

MEDIUM · 6.8 CVSS v3.1 Published 2021-12-06
Fix available
A fix is available. Upgrade to 15.2.4 or later.
See remediation →
74/100
Remediation priority · Elevated
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
When a user has admin rights in Serv-U Console, the user can move, create and delete any files are able to be accessed on the Serv-U host machine.

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 confidence

In SolarWinds Serv-U FTP server, admin users with access to the Serv-U Console can perform unrestricted file system operations on the host machine, including creating, moving, and deleting files beyond the intended scope of the application. This represents an improper authorization vulnerability where console admin privileges allow arbitrary file system access.

MitigationRestrict Serv-U Console administrative access to only trusted, verified personnel and apply any vendor security updates. Implement network segmentation to limit exposure of the administrative interface.

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
Serv UApplication
Affected:< 15.2.4= 15.2.4= 15.2.5

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
High
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N

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 Serv-U installation and version
    Locate the Serv-U installation directory and check the version. Common locations include C:\Program Files\SolarWinds\Serv-U on Windows or /opt/serv-u on Linux. Look for version information in the Serv-U administration interface, in a version.txt file, or by running 'Serv-U -v' from the installation directory.
    Affected if The installed version is 15.2.4, 15.2.5, or any version lower than 15.2.4.
  2. Verify Serv-U Console is accessible
    Check if the Serv-U Console administrative web interface is exposed and accessible. This is typically hosted on port 8787 by default. Confirm the service is running and the management interface is reachable.
    Affected if The Serv-U Console administrative interface is accessible on the network.
  3. Confirm admin user accounts exist
    Review the Serv-U user management configuration to identify accounts with administrative privileges. Check the Serv-U Console user settings or the XML configuration files in the installation directory that define administrative roles.
    Affected if There are user accounts configured with administrative access to the Serv-U Console.
  4. Check file system access scope
    Examine the Serv-U configuration for restrictions on file system operations. Look for configuration settings that define allowed directories and access boundaries for admin users. Compare the configured scope against what users can actually access.
    Affected if The configuration allows admin users to access directories outside the intended scope or shows no enforced restrictions on file system operations.

A user is affected if their Serv-U installation version is 15.2.4, 15.2.5, or any version below 15.2.4 AND the Serv-U Console administrative interface is accessible with admin user accounts configured.

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.

dbcve · scoped
Upgrade available Upgrade to 15.2.4 or later
Fixed in 15.2.4
Interim mitigation

Restrict Serv-U Console administrative access to only trusted, verified personnel and apply any vendor security updates. Implement network segmentation to limit exposure of the administrative interface.

Recommended fix Moderate confidence

Serv-U 15.2.6 or later

  1. 1. Identify the current Serv-U version installed by checking the Serv-U Console or using the version check command
  2. 2. Download the latest stable version of Serv-U from the official SolarWinds download portal
  3. 3. Create a full backup of the current Serv-U configuration and all user data
  4. 4. Schedule a maintenance window to minimize disruption to services
  5. 5. Stop the Serv-U service before performing the upgrade
  6. 6. Install the upgraded version (15.2.6 or later) following the SolarWinds installation documentation
  7. 7. After installation, verify the version number matches the expected fixed release
  8. 8. Test file operations through the Serv-U Console to confirm the improper access control vulnerability is remediated
Caveat Review release notes for any configuration or feature changes between 15.2.4/15.2.5 and the target version; test critical file transfer workflows before deploying to production

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Serv U Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

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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-2021-35245 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