CVE-2026-41235
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 · uneditedFroxlor is open source server administration software. Version 2.3.6 lets administrators configure `system.available_shells` as the approved shell list that customers may assign to FTP users. However, the server-side FTP account handlers do not enforce that whitelist when processing add or edit requests. As a result, an authenticated customer with shell delegation enabled can submit an arbitrary shell such as `/bin/bash` even when the panel UI only offers more restricted choices. In deployments that use the default `nssextrausers` integration, the attacker-controlled shell is then propagated into the system account database, leading to real host shell access. Version 2.3.7 fixes the 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 confidenceFroxlor 2.3.6 has an authorization bypass in the server-side FTP account handlers. While administrators can configure a whitelist of allowed shells via `system.available_shells`, the handlers fail to enforce this whitelist when processing add or edit requests. Authenticated customers with shell delegation enabled can submit arbitrary shells like /bin/bash, bypassing UI restrictions. In deployments using the nssextrausers integration, this allows attackers to gain actual host shell access.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Low
- Authentication
- X
- User interaction
- None
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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 Froxlor versionCheck the installed Froxlor version by accessing the admin panel or inspecting the version file (commonly found in the Froxlor installation directory or via admin interface system info).Affected if The installed version is exactly 2.3.6 (prior versions may also be vulnerable if they lack server-side whitelist enforcement).
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Determine if shell delegation is enabledReview customer account settings in the Froxlor admin panel under customer management, looking for shell delegation or shell access permissions assigned to customer accounts.Affected if Any customer account has shell delegation or shell access permission enabled; this is the condition that allows the bypass to occur.
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Inspect system shell whitelist configurationLocate the system.available_shells configuration setting in Froxlor configuration files or database settings that define the permitted shells for customer use.Affected if The system.available_shells whitelist exists but is not being enforced server-side during FTP account add/edit operations.
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Check FTP account shell assignmentsList all FTP accounts in the system (via Froxlor FTP management or by querying the account database) and inspect the assigned shell field for each account.Affected if Any FTP account has a shell assigned that is not in the intended system.available_shells whitelist, such as /bin/bash when a restricted shell was expected.
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Identify nssextrausers integration usageCheck the Froxlor system settings or configuration to determine if the nssextrausers integration method is enabled for system account management.Affected if nssextrausers integration is active, as this allows attacker-controlled shell values to propagate directly to the system account database.
A user is affected if running Froxlor 2.3.6 with shell delegation enabled for any customer and nssextrausers integration active, resulting in FTP accounts with unauthorized shell assignments outside the intended whitelist.
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 · scopedUpgrade to Froxlor version 2.3.7. If immediate patching is not possible, disable shell delegation for customer FTP accounts and review existing accounts for unauthorized shell assignments.
2.3.7
- Backup the current Froxlor installation and database before proceeding
- Download Froxlor version 2.3.7 from the official repository or releases page
- Extract the new version files to the web server document root, preserving local configuration
- Run the included database migration scripts if any are provided in the release
- Clear any application caches to ensure new code is loaded
- Verify the upgrade was successful by logging into the admin panel
- Confirm that system.available_shells is properly enforced by attempting to assign an unapproved shell via the FTP account interface
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-41235 — 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-2026-41235 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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- Version or environment caveats, and links to real fixes
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