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#!/usr/bin/python3
# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
#
# SPDX-License-Identifier: MPL-2.0
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, you can obtain one at https://mozilla.org/MPL/2.0/.
#
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.
import socket
import time
import pytest
pytest.importorskip("dns")
import dns.message
import dns.query
import dns.rcode
def test_cve_2023_3341(named_port, control_port):
depth = 4500
# Should not be more than isccc_ccmsg_setmaxsize(&conn->ccmsg, 32768)
total_len = 10 + (depth * 7) - 6
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
data = b"".join(
[
total_len.to_bytes(4, "big"), # <total lenght>
b"\x00\x00\x00\x01", # <version>
b"\x01\x41", # <size><name>
]
)
for i in range(depth, 0, -1):
l = (i - 1) * 7
t = b"".join(
[
b"\x02", # ISCCC_CCMSGTYPE_TABLE
l.to_bytes(4, "big"), # <size>
b"\x01\x41", # <size><name>
]
)
data = b"".join([data, t])
s.connect(("10.53.0.2", control_port))
s.sendall(data)
# Wait for named to (possibly) crash
time.sleep(10)
msg = dns.message.make_query("version.bind", "TXT", "CH")
ans = dns.query.udp(msg, "10.53.0.2", timeout=10, port=named_port)
assert ans.rcode() == dns.rcode.NOERROR
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