vulnerability / NVI-00007176 / Revision 3
elFinder: CSRF in netmount allows forced FTP mounts and server-side FTP connections
GitHub lists this reviewed advisory for studio-42/elfinder. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.4 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.177%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.07237. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
studio-42/elfinder
source listed< 2.1.70
### Summary The PHP connector's CSRF gate protects many mutating commands, but it does not protect the `netmount` connector command. In the shipped minimal connector setup, FTP network mounting is enabled by default, so a cross-site request can force an elFinder instance to mount an attacker-chosen FTP endpoint in the victim's session and cause the server to initiate an outbound FTP connection without the `X-elFinder-CSRF` token that other state-changing commands require. This was confirmed locally against `Studio-42/elFinder` at commit `ec5f811dc321a053085b994966f553eaaab58721`, corresponding to the repository's documented stable release `2.1.69` / API revision `2.1.69`. ### Details The connector has an explicit allowlist of commands that require CSRF validation in `php/elFinderConnector.class.php:79-92`. That list includes state-changing commands such as `mkdir`, `mkfile`, `paste`, `put`, `rename`, `rm`, `upload`, `archive`, `extract`, `resize`, and `chmod`, but it omits `netmount`. The enforcement point in `php/elFinderConnector.class.php:376-381` calls `validateCsrfToken()` only when the command appears in that list. `netmount` is a first-class connector command declared in
studio-42/elfinder
source listedECOSYSTEM: introduced 0; fixed 2.1.70
### Summary The PHP connector's CSRF gate protects many mutating commands, but it does not protect the `netmount` connector command. In the shipped minimal connector setup, FTP network mounting is enabled by default, so a cross-site request can force an elFinder instance to mount an attacker-chosen FTP endpoint in the victim's session and cause the server to initiate an outbound FTP connection without the `X-elFinder-CSRF` token that other state-changing commands require. This was confirmed locally against `Studio-42/elFinder` at commit `ec5f811dc321a053085b994966f553eaaab58721`, corresponding to the repository's documented stable release `2.1.69` / API revision `2.1.69`. ### Details The connector has an explicit allowlist of commands that require CSRF validation in `php/elFinderConnector.class.php:79-92`. That list includes state-changing commands such as `mkdir`, `mkfile`, `paste`, `put`, `rename`, `rm`, `upload`, `archive`, `extract`, `resize`, and `chmod`, but it omits `netmount`. The enforcement point in `php/elFinderConnector.class.php:376-381` calls `validateCsrfToken()` only when the command appears in that list. `netmount` is a first-class connector command declared in
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- vendor patch
The original advisory lists fixed boundaries 2.1.70 for studio-42/elfinder. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-9hjf-w35w-6vx2 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-9hjf-w35w-6vx2 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-81890 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.