vulnerability / NVI-00017610 / Revision 1
File Browser: Authentication Bypass via Proxy Auth Header Forgery
GitHub lists this reviewed advisory for github.com/filebrowser/filebrowser/v2. 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.
9.1 critical
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/filebrowser/filebrowser/v2
source listed>= 2.0.0-rc.1, <= 2.63.18
## Summary When FileBrowser is configured with proxy authentication (`auth.method=proxy`), any unauthenticated attacker who can reach the server directly can impersonate **any user - including admin** - by sending a single forged HTTP header. No credentials are required. Additionally, specifying a non-existent username causes the server to **automatically create a new user account**, providing an account creation primitive with no authorization. **This is an already known issue that has been documented in the documentation for several years, but has not been documented as a vulnerability before.** ## Severity **HIGH** - CVSS 3.1: **8.1** (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N) ## Affected Component - **File:** `auth/proxy.go`, lines 21-28 - **CWE:** CWE-287 (Improper Authentication), CWE-290 (Authentication Bypass by Spoofing) - **Affected versions:** All versions supporting `auth.method=proxy` ## Prerequisite: Proxy Auth Must Be Enabled This vulnerability is **NOT exploitable on default configuration** (`a
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. GitHub Advisory Database
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-xqp3-jq6g-x3qm ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.