SECURITY: No validation on volume host paths allows arbitrary filesystem access #35

New Issue

2026-02-16T06:56:31+01:00

clawbot commented

2026-02-16 06:56:31 +01:00

Severity: HIGH

File: `internal/handlers/app.go` lines 525-545 (HandleVolumeAdd)

Description

When adding a volume mount, the host_path form value is accepted without any validation or sanitization. An authenticated user can specify any host path (e.g., /etc/shadow, /var/run/docker.sock, /) and it will be bind-mounted into the container.

While this is a single-user system and the user is already an admin, this is still a defense-in-depth concern:

If the session is hijacked, the attacker gets arbitrary filesystem access via container mounts
There's no allowlist or denylist of paths
No warning to the user about dangerous mounts

Suggested Fix

Add a configurable allowed_volume_prefix (e.g., /data/) that restricts host paths
At minimum, reject paths like /etc, /var/run/docker.sock, /proc, /sys
Validate that paths are absolute and normalized (no .. traversal)

func isAllowedHostPath(path string) bool {
    cleaned := filepath.Clean(path)
    if cleaned != path {
        return false // path contains .., //, etc.
    }
    blocked := []string{"/etc", "/proc", "/sys", "/dev", "/var/run/docker.sock"}
    for _, b := range blocked {
        if strings.HasPrefix(cleaned, b) {
            return false
        }
    }
    return true
}

## Severity: HIGH ## File: `internal/handlers/app.go` lines 525-545 (HandleVolumeAdd) ## Description When adding a volume mount, the `host_path` form value is accepted without any validation or sanitization. An authenticated user can specify any host path (e.g., `/etc/shadow`, `/var/run/docker.sock`, `/`) and it will be bind-mounted into the container. While this is a single-user system and the user is already an admin, this is still a defense-in-depth concern: - If the session is hijacked, the attacker gets arbitrary filesystem access via container mounts - There's no allowlist or denylist of paths - No warning to the user about dangerous mounts ## Suggested Fix 1. Add a configurable `allowed_volume_prefix` (e.g., `/data/`) that restricts host paths 2. At minimum, reject paths like `/etc`, `/var/run/docker.sock`, `/proc`, `/sys` 3. Validate that paths are absolute and normalized (no `..` traversal) ```go func isAllowedHostPath(path string) bool { cleaned := filepath.Clean(path) if cleaned != path { return false // path contains .., //, etc. } blocked := []string{"/etc", "/proc", "/sys", "/dev", "/var/run/docker.sock"} for _, b := range blocked { if strings.HasPrefix(cleaned, b) { return false } } return true } ```

sneak commented

2026-02-16 07:09:03 +01:00

dupe #20

sneak closed this issue

2026-02-16 07:09:03 +01:00

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Reference: sneak/upaas#35

SECURITY: No validation on volume host paths allows arbitrary filesystem access #35

Severity: HIGH

File: internal/handlers/app.go lines 525-545 (HandleVolumeAdd)

Description

Suggested Fix

File: `internal/handlers/app.go` lines 525-545 (HandleVolumeAdd)