CVE-2021-41550
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 · uneditedLeostream Connection Broker 9.0.40.17 allows administrator to upload and execute Perl code.
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 confidenceLeostream Connection Broker 9.0.40.17 contains an authenticated file upload vulnerability that allows an administrator to upload malicious Perl files and execute them on the server, achieving remote code execution.
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= 9.0.40.17CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/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 Leostream Connection Broker installationIdentify if Leostream Connection Broker software is installed on the system. Check for installation directories, services, or the web application running on common ports (typically port 80/443).Affected if Leostream Connection Broker is installed and running as a web application
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Determine the installed versionAccess the Leostream web interface admin panel and navigate to the About or System Information page to view the software version. Alternatively, check installation files or registry entries for version metadata.Affected if The installed version is exactly 9.0.40.17
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Confirm web interface accessibilityCheck if the Leostream web interface is accessible over the network. Attempt to reach the login page at the expected URL (such as /leostream or /broker).Affected if The web interface is accessible externally or to untrusted users
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Verify administrator access controlsReview authentication settings and determine whether the administrator login page is exposed. Check if default credentials are in use or if authentication can be bypassed.Affected if Administrator authentication is enabled but accessible to potential attackers
If the Leostream Connection Broker version is exactly 9.0.40.17 and the web interface is accessible, the authenticated file upload vulnerability is present and could allow remote code execution via malicious Perl file uploads.
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 dataRestrict and validate file uploads, store uploaded files outside the web root, disable script execution in upload directories, and implement strict allowlist validation for permitted file types.
- Consultation2.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-41550 — 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-2021-41550 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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