File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.33.8, when a shell interpreter is configured (e.g. /bin/sh -c), the command allowlist can be bypassed through shell metacharacters. The allowlist validates only the first token of user input, but the entire raw string is handed to the shell — semicolons, pipes, backticks, and $() all work to chain arbitrary commands after a permitted one. This vulnerability is fixed in 2.33.8.

Affected: Go: github.com/filebrowser/filebrowser/v2

> [!NOTE] > **This feature has been disabled by default for all installations from v2.33.8 onwards, including for existent installations**. To exploit this vulnerability, the instance administrator must turn on a feature and ignore all the warnings about known vulnerabilities. We're publishing this new advisory to make it clear that all vulnerabilities concerning this feature are disclosed. > > For more information about tracking vulnerability issues related to the Command Execution features, check https://github.com/filebrowser/filebrowser/issues/5199.

## Summary

When a shell interpreter is configured (e.g. `/bin/sh -c`), the command allowlist can be bypassed through shell metacharacters. The allowlist validates only the first token of user input, but the entire raw string is handed to the shell — semicolons, pipes, backticks, and `$()` all work to chain arbitrary commands after a permitted one.

This is a distinct issue from CVE-2025-52995 (regex partial matching, fixed in 2.33.10) and CVE-2025-52903 (GTFOBins-style subcommands). The `slices.Contains` fix does not prevent this bypass.

## Affected Location

- `runner/parser.go`, function `ParseCommand` (lines 10-25) - `http/commands.go`, function `commandsHandler` (lines 72-86)

## Root Cause

`ParseCommand` extracts the first token via `SplitCommandAndArgs` for the allowlist check, then passes the entire raw input to the shell:

```go func ParseCommand(s *settings.Settings, raw string) (command []string, name string, er…