Onionr/src/bigbrother/ministry/ofexec.py

83 lines
3.2 KiB
Python

"""Onionr - Private P2P Communication.
Prevent eval/exec/os.system and log it
"""
import base64
import platform
import logger
from utils import identifyhome
from onionrexceptions import ArbitraryCodeExec
"""
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
def block_system(cmd):
"""Prevent os.system except for whitelisted commands+contexts."""
allowed = 'taskkill /PID '
is_ok = False
if platform.system() == 'Windows':
if cmd.startswith(allowed):
for c in cmd.split(allowed)[1]:
if not c.isalnum() or c not in ('/', 'F', ' '):
break
else:
is_ok = True
if not is_ok:
logger.warn('POSSIBLE EXPLOIT DETECTED, SEE LOGS', terminal=True)
logger.warn(f'POSSIBLE EXPLOIT: shell command not in whitelist: {cmd}')
raise ArbitraryCodeExec('os.system command not in whitelist')
def block_exec(event, info):
"""Prevent arbitrary code execution in eval/exec and log it."""
# because libraries have stupid amounts of compile/exec/eval,
# We have to use a whitelist where it can be tolerated
# Generally better than nothing, not a silver bullet
whitelisted_code = [
'netrc.py',
'shlex.py',
'gzip.py',
'<werkzeug routing>',
'werkzeug/test.py',
'multiprocessing/popen_fork.py',
'multiprocessing/util.py',
'multiprocessing/connection.py',
'onionrutils/escapeansi.py',
'stem/connection.py',
'stem/response/add_onion.py',
'stem/response/authchallenge.py',
'stem/response/getinfo.py',
'stem/response/getconf.py',
'stem/response/mapaddress.py',
'stem/response/protocolinfo.py'
]
home = identifyhome.identify_home()
code_b64 = base64.b64encode(info[0].co_code).decode()
for source in whitelisted_code:
if info[0].co_filename.endswith(source):
return
if 'plugins/' in info[0].co_filename:
return
logger.warn('POSSIBLE EXPLOIT DETECTED, SEE LOGS', terminal=True)
logger.warn('POSSIBLE EXPLOIT DETECTED: ' + info[0].co_filename)
logger.warn('Prevented exec/eval. Report this with the sample below')
logger.warn(f'{event} code in base64 format: {code_b64}')
raise ArbitraryCodeExec("Arbitrary code (eval/exec) detected.")