# GHSA-68w4-83fh-f2w8: `Api.getUserData` (legacy) and `Api.get_userdata` are declared with `@permission(Perms.ANY)` and are reachable at `/api/getUserDa

> Low-privilege users can brute-force administrator passwords via exposed API endpoints due to a flawed permission check, leading to full account takeover.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Oct 2026

## What is GHSA-68w4-83fh-f2w8?

GHSA-68w4-83fh-f2w8 is a missing authorization vulnerability in pyload-ng, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

## Summary

`Api.getUserData` (legacy) and `Api.get_userdata` are declared with `@permission(Perms.ANY)` and are reachable at `/api/getUserData` and `/api/get_userdata`. Because `Perms.ANY == 0` and pyLoad's permission check is a bitmask AND, that gate is a no-op: **every authenticated account passes, including one holding zero permission bits.**

Both methods are thin wrappers around `check_auth()`, which the maintainers deliberately restricted to administrators by omitting `@permission` (no entry in `perm_map`, so `is_authorized()` returns `False` for non-admins). The wrappers undo that protection.

An attacker holding the lowest-privileged account in the system therefore has a clean binary oracle on the **administrator password**, with no account lockout anywhere in the codebase, and with the 100 req/min rate limiter bypassable by rotating `X-Forwarded-For`.

## Affected code

`src/pyload/core/api/__init__.py:1446` and `:1464`

```python
    #: Old API
    @permission(Perms.ANY)
    @get
    def getUserData(self, username: str, password: str) -> OldUserData:
        """
        similar to `check_auth` but returns UserData type.
        """
        user = self.check_auth(username, password)
        ...

    @permission(Perms.ANY)
    @get
    def get_userdata(self, username: str, password: str) -> UserData:
        user = self.check_auth(username, password)
        ...
```

## Root cause

`src/pyload/core/api/__init__.py:57`

```python
class Perms(IntFlag):
    ANY = 0  #: requires no permission, but login
```

`src/pyload/core/api/__init__.py:108`

```python
def has_permission(user_perms: Perms, required_perms: Perms):
    return required_perms == (user_perms & required_perms)
```

For `required_perms == 0` this evaluates to `0 == (user_perms & 0)` → `0 == 0` → **always `True`**. The `@permission(Perms.ANY)` gate therefore admits every authenticated principal regardless of which permission bits they hold.

Contrast with the intended admin-only primitive, `src/pyload/core/api/__init__.py:1396`:

```python
    @legacy("checkAuth")
    @get
    def check_auth(self, username: str, password: str) -> dict[str, Any]:
```

`check_auth` has **no** `@permission`; `is_authorized()` at `api/__init__.py:1430` returns `False` for non-admins. The two wrappers carry `Perms.ANY` and restore access for everyone.

Because both wrappers also carry `@get`, they are placed in `method_map` and are directly routable via `/api/<func>`.

## Amplifiers

**1. No lockout.** There is no failed-login counter, delay, or ban anywhere in the codebase. A failed guess costs the attacker only one PBKDF2 computation.

**2. Rate limiting is bypassable.** `/api/*` applies `rate_limit(count=100, period=60)` (`src/pyload/webui/app/blueprints/api_blueprint.py:25`), which buckets on a fully client-controlled header (`src/pyload/webui/app/helpers.py:446`):

```python
client_ip = flask.request.headers.get("X-Forwarded-For", "").split(",")[0].strip() \
    or flask.request.remote_addr
```

Rotating `X-Forwarded-For` per request yields a fresh bucket each time. Notably, `is_loopback_request()` in the **same file** (`helpers.py:288-294`) explicitly treats the presence of `X-Forwarded-For` / `X-Real-IP` / `Forwarded` as untrustworthy — the same guard was evidently not applied inside `rate_limit()`.

## Impact

Online brute force of the administrator account leading to full administrative takeover. A successful response additionally discloses the target account's `id`, `name`, `email`, `role`, and `permission` bits.

## Proof of concept

Verified against 0.5.0b3, commit `a5b008958`.

Setup: stock instance with admin `pyload`, plus a non-admin user `bob` created with `role=USER` and `permission=0`.

**Step 1 — establish that `bob` is genuinely unprivileged:**

```
GET /api/checkAuth?username=pyload&password=pyload   ->  401 {"error": "Access denied"}
GET /api/getAllUserData                              ->  401 {"error": "Access denied"}
```

**Step 2 — the flaw. Same user, same session, `Perms.ANY` gate:**

```
GET /api/getUserData?username=pyload&password=WRONG
  -> 200 {"name": null, "email": null, "role": null, "permission": null, "template_name": null}

GET /api/getUserData?username=pyload&password=pyload
  -> 200 {"name": "pyload", "email": "", "role": 0, "permission": 0, "template_name": "default"}
```

`role: 0` is `Role.ADMIN`. `get_userdata` behaves identically. This is a perfect yes/no oracle.

**Step 3 — measured brute force and recovery.** Run as `bob` (`permission = 0`), admin password set to a 2-character value, `X-Forwarded-For` rotated on every request:

```
attempts         : 667
elapsed          : 39.7s   (16.8 guesses/sec)
429 rate-limits  : 0
account lockout  : NONE - same session authenticated throughout
RECOVERED SECRET : 'zq'   (true value 'zq')   match=True
```

**Step 4 — full takeover with the recovered secret:**

```
POST /login as pyload/<recovered>       ->  HTTP 302  (authenticated as admin)
GET  /api/getAllUserData (admin-only)  ->  HTTP 200  (full user dump)
```

Measured throughput is 17-47 guesses/sec/thread. The only bound is PBKDF2-HMAC-SHA256 at 100,000 iterations in `src/pyload/core/database/user_database.py:14`, not any rate limit.

## Suggested remediation

- Remove `@permission(Perms.ANY)` from `getUserData` and `get_userdata`, or drop them entirely — they are legacy compatibility shims, and modern callers already use the admin-only `check_auth`.
- Structurally: `Perms.ANY = 0` makes `has_permission()` vacuous, so **any** method decorated `@permission(Perms.ANY)` silently becomes public to every logged-in user. Give `ANY` a real bit value, or handle it explicitly in `has_permission()` as "requires an authenticated session".
- Do not trust `X-Forwarded-For` unless a trusted-proxy deployment is explicitly configured. Otherwise bucket `rate_limit()` on `request.remote_addr`, or add the same guard `is_loopback_request()` already uses.
- Add per-account failed-authentication throttling or lockout.
- Consider `hmac.compare_digest()` in `_check_password()` (`src/pyload/core/database/user_database.py:61` uses a plain `==` on the derived hash, contradicting the "always use compare_digest" guidance two files away).

## Notes for triage

There is no `0.5.0b3` release on PyPI. The `develop` branch auto-publishes dev builds (`setup.py:86` appends `.dev<build>` to the `VERSION` file); the newest at time of testing was `0.5.0b3.dev101`. The `Perms.ANY = 0` design is long-standing, but only the `0.5.0b3.dev*` line was verified here — please confirm whether `0.5.0b2.*` and `0.4.x` are affected before finalizing the version range.

## Which versions are affected by GHSA-68w4-83fh-f2w8?

2 open source packages ship an affected version, including pyload-ng.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pyload-ng` | PyPI | From 0.5.0b3.dev1 to 0.5.0b3.dev101 | None |
| `pyload-ng` | PyPI | From 0.5.0b3.dev1 to 0.5.0b3.dev101 | None |

## How do I fix GHSA-68w4-83fh-f2w8?

No fix has been published for GHSA-68w4-83fh-f2w8 yet. Limit exposure of the affected software until one is available.

## Is GHSA-68w4-83fh-f2w8 being exploited?

There is no known exploitation of GHSA-68w4-83fh-f2w8 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-68w4-83fh-f2w8 and fix it if it is affected.

What it is: GHSA-68w4-83fh-f2w8 is a missing authorization vulnerability in pyload-ng, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-68w4-83fh-f2w8 in the wild and no public exploit code.

Affected packages and fixed versions:
- pyload-ng (PyPI): affected from 0.5.0b3.dev1 up to 0.5.0b3.dev101; no fix listed
- pyload-ng (PyPI): affected from 0.5.0b3.dev1 up to 0.5.0b3.dev101; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-68w4-83fh-f2w8/ (Markdown: https://insights.sbomify.com/GHSA-68w4-83fh-f2w8/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-68w4-83fh-f2w8

---
From sbomify Insights: https://insights.sbomify.com/GHSA-68w4-83fh-f2w8/
Summaries are generated and may contain mistakes; the official description above is the record.