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[critical] fix: [html_to_markdown] block unspecified, shared, ULA and link-local ranges in the URL safety check #908

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[critical] fix: [html_to_markdown] block unspecified, shared, ULA and link-local ranges in the URL safety check #908

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5 changes: 5 additions & 0 deletions misp_modules/modules/expansion/html_to_markdown.py
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Original file line number Diff line number Diff line change
Expand Up @@ -28,12 +28,17 @@


BLOCKED_RANGES = [
ipaddress.ip_network("0.0.0.0/8"),
ipaddress.ip_network("127.0.0.0/8"),
ipaddress.ip_network("10.0.0.0/8"),
ipaddress.ip_network("100.64.0.0/10"),
ipaddress.ip_network("172.16.0.0/12"),
ipaddress.ip_network("192.168.0.0/16"),
ipaddress.ip_network("169.254.0.0/16"),
ipaddress.ip_network("::/128"),
ipaddress.ip_network("::1/128"),
ipaddress.ip_network("fc00::/7"),
ipaddress.ip_network("fe80::/10"),
]
MAX_REDIRECTS = 10

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23 changes: 23 additions & 0 deletions tests/test_html_to_markdown.py
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Expand Up @@ -43,6 +43,29 @@ def test_blocks_hostnames_resolving_to_ipv4_mapped_blocked_addresses(self):
):
self.assertFalse(is_safe_url("http://example.test/"))

def test_blocks_unspecified_shared_ula_and_link_local_literals(self):
blocked_urls = (
"http://0.0.0.0/",
"http://100.64.0.1/",
"http://[::]/",
"http://[fc00::1]/",
"http://[fd12:3456::1]/",
"http://[fe80::1]/",
"http://[::ffff:0.0.0.0]/",
"http://[::ffff:100.64.0.1]/",
)

for url in blocked_urls:
with self.subTest(url=url):
self.assertFalse(is_safe_url(url))

def test_blocks_hostnames_resolving_to_ula_addresses(self):
with patch(
"misp_modules.modules.expansion.html_to_markdown.socket.getaddrinfo",
return_value=[(None, None, None, None, ("fd00::1", 0, 0, 0))],
):
self.assertFalse(is_safe_url("http://example.test/"))

def test_rejects_url_without_hostname(self):
self.assertFalse(is_safe_url("http:///missing-host"))

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