google-labs-jules[bot]
8b4280d5dd
Modified `is_private_ip` in `app/utils/network.py` to fail securely by returning True (blocking the request) when a hostname cannot be resolved. The previous implementation failed open, creating a risk for Server-Side Request Forgery (SSRF) and DNS rebinding attacks. Updated corresponding tests to expect the secure behavior. Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
35 lines
1.3 KiB
Python
35 lines
1.3 KiB
Python
import ipaddress
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import logging
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import socket
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logger = logging.getLogger(__name__)
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def is_private_ip(hostname: str) -> bool:
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"""
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Check if a hostname resolves to a private/internal IP address.
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Protects against SSRF attacks by blocking access to internal networks.
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"""
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try:
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# Try to parse as IP address directly
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ip = ipaddress.ip_address(hostname)
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return ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_reserved
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except ValueError:
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# Not a direct IP, try to resolve hostname
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try:
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# Get all IP addresses for this hostname
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addr_info = socket.getaddrinfo(hostname, None)
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for info in addr_info:
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ip_str = info[4][0]
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ip = ipaddress.ip_address(ip_str)
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# Block if ANY resolved IP is private/internal
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if ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_reserved:
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return True
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return False
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except (socket.gaierror, socket.error):
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# Cannot resolve.
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# Fail securely: block unresolved domains to prevent DNS rebinding
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# and SSRF bypasses via unresolvable addresses.
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logger.warning(f"Could not resolve hostname (blocking securely): {hostname}")
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return True
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