SlopBro

Some of the Python was written by an LLM. (You think I wanted to write a Python 2.7/3.x-compatible WebSocket client?) The rest is good, old-fashioned human slop. It's the spirit of the times, you know?

Overview

SlopBro is a proof-of-concept exploit for the jsserver vulnerability in LG TVs.

I tried to make it compatible with Python 2.7 and 3.x with no dependencies outside the standard library so that it could be run on all versions of webOS TV. Unfortunately, the Python 2.7 environment on webOS 6 (and presumably older) is missing the HTTP server stuff, so it was kind of a waste of time. Oh well.

Python 2 support has now been dropped. SSAP never worked right via loopback anyway. The script still uses only the standard library.

I've only lightly tested it (remember: slop!), but people have gotten it to work on a bunch of webOS versions.

SlopBro has been used successfully against webOS 4–11 and now includes a workaround for LG's attempt to patch the jsserver vulnerability. (While it might work all the way back to webOS 3.4.2, I recommend using dejavuln-autoroot for webOS 3.5 and 4.x.)

How it works

slopbro.py is the main script. It performs the following steps:

Starts an HTTP server to serve the exploit page and payloads.
Opens an SSAP connection to the TV.
Launches a WAM app pointing at the exploit page index.html.

Pages running in the context of certain WAM apps can make privileged Luna requests. When loaded on the TV, index.html does the following:

Displays status and debug info on the TV screen.
Downloads files for a fake com.webos.service.jsserver package from the HTTP server.
Runs the package using the jsserver vulnerability.

The entry point of the fake com.webos.service.jsserver package is main.js, which is executed with root privileges. It is responsible for launching autoroot.sh, which installs Homebrew Channel and enables persistence.

Running

Run the script with Python 3, passing the IP address of your TV:

python slopbro.py [--debug] [--curl-insecure] [--fake-service-path <PATH>|--no-fake-service-path] [--local-ip <LOCAL IP>] [--webos-version <VERSION>] [--asset-source <auto|dir|embedded>] [--test-server <simple|payload>] [<TV IP ADDRESS>]

Use python3 slopbro.py --help for the full option reference.

Accept the pairing prompt on the target TV. (The credentials will be saved in a .key file for future use.)

Options

The --debug option enables extra output on the TV screen as well as in autoroot.log.

The --curl-insecure option passes -k to curl when downloading Homebrew Channel, disabling TLS certificate verification. Use it only when necessary (e.g., when your TV does not have the correct date due to SDP being blocked).

The --fake-service-path option specifies the fake service path used to bypass the service launch patch. It defaults to /usr/palm/services/com.palm.service.devmode. Use --no-fake-service-path to disable the bypass and omit the fake-service-path query parameter.

The --local-ip option allows you to specify the local IP address manually, which can be useful if the script guesses the wrong IP address.

The --webos-version option specifies the TV's webOS version and limits the target apps to those configured for that major version. Dotted versions such as 6.5 are accepted and treated as major version 6.

The version is not currently auto-detected, so you may need to specify it if the selected app fails.

The --asset-source option allows you to specify where the script should look for assets (auto, dir, embedded).

The --test-server option starts the local HTTP server and prints its URL instead of connecting to the TV over SSAP, so you can test connectivity manually by opening the URL in a browser. It doesn't pair with or launch anything on the TV. The <TV IP ADDRESS> argument is optional but recommended in both modes below; if omitted, the script guesses a LAN-facing local IP, which may be wrong. Two modes are available:

simple: serves a fixed plain-text response to confirm basic HTTP reachability only.
payload: serves the real exploit/payload files (same as a normal run) without doing any SSAP pairing or launching, so you can load index.html directly in a browser to examine the payload itself.

Packaging

In addition to serving files from the wwwroot directory, SlopBro can be distributed as a single file with embedded assets.

Building a single-file package

The packaging tool requires Python 3.12 or newer (independently of the launcher's runtime requirements). Generate a standalone file with:

python3 tools/package_single_file.py --out dist/slopbro_packed.py

Then run it directly (no wwwroot required):

python3 dist/slopbro_packed.py 192.168.1.50

You can also explicitly specify where it should look for assets (embedded, dir):

python3 dist/slopbro_packed.py --asset-source embedded 192.168.1.50

By default (auto mode), embedded assets are preferred over files if both are present.

Tests

Run the CLI and HTTP handler regression tests without connecting to a TV:

python3 -m unittest discover -s tests -v

Troubleshooting

slopbro.py guesses what the local IP address is and might get it wrong. If you don't see any connections back to the HTTP server, try manually specifying the IP address with --local-ip.
Make sure there are no weird network issues between your TV and wherever you're running SlopBro. Remember that connections need to work in both directions.
Use --test-server simple to check basic HTTP connectivity from the TV's browser without needing SSAP pairing to work first.

Credits

IDK, Claude Sonnet 4.6?

(dangbei-overlay from dangbro; jsserver vulnerability first publicly disclosed in jsbro-autoroot.)

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.

See COPYING for details.