Files
odysseus/tests/test_url_safety.py
Joeseph Grey b3f8b77317 fix(url-safety): reject RFC 6598 shared address space in strict mode (#5474)
* security(url-safety): reject RFC 6598 shared address space in strict mode

Strict mode (block_private=True) is a full SSRF lockdown, but it only
rejected is_private and is_loopback targets. CPython does not classify RFC
6598 shared/CGNAT space (100.64.0.0/10) as is_private (it is "shared", not
"private"), so a public redirect into 100.64.0.1 passed the per-hop guard
and still issued the request to a potentially internal CGNAT service.

not is_global would also exclude it, but only on CPython 3.11.10+/3.12.4+/
3.13+; the CI matrix runs 3.11/3.12, so reject the range explicitly to stay
correct across patch levels and the 3.14 runtime image. Default local-first
mode is unchanged. Adds strict-mode coverage for shared, non-global, and
public targets.

* docs(url-safety): correct CGNAT is_global rationale in strict-mode comment

The prior comment claimed `not is_global` catches 100.64.0.0/10 only on
CPython 3.11.10+/3.12.4+/3.13+. That is inaccurate for CGNAT: is_global
is False for 100.64.0.1 on every supported version (verified 3.10-3.14).
The version-fragility applies to other ranges gh-113171 touched, not CGNAT.
The explicit range reject is still the right choice; restate the reason as
is_private not covering shared space, and not coupling strict mode to
is_global's broader, cross-version definition. No behavior change.
2026-07-18 12:36:27 -06:00

118 lines
4.2 KiB
Python

"""Tests for outbound URL safety / SSRF hardening (src/url_safety.py).
A stub resolver is injected so the tests never touch real DNS.
"""
from src.url_safety import check_outbound_url
def _resolver(mapping):
def resolve(host):
if host in mapping:
return mapping[host]
raise OSError(f"unresolvable: {host}")
return resolve
PUBLIC = _resolver({"example.com": ["93.184.216.34"]})
LOOPBACK = _resolver({"localhost": ["127.0.0.1"]})
LAN = _resolver({"nas.local": ["192.168.1.50"]})
METADATA = _resolver({"evil.example": ["169.254.169.254"]})
MAPPED_METADATA = _resolver({"evil6.example": ["::ffff:169.254.169.254"]})
def test_non_http_scheme_blocked():
for url in ("file:///etc/passwd", "ftp://x/y", "gopher://h", "redis://h:6379"):
ok, reason = check_outbound_url(url, resolver=PUBLIC)
assert ok is False, url
assert "scheme" in reason
def test_missing_host_or_empty_blocked():
assert check_outbound_url("", resolver=PUBLIC)[0] is False
assert check_outbound_url("http://", resolver=PUBLIC)[0] is False
def test_public_url_allowed():
ok, reason = check_outbound_url("https://example.com/v1/embeddings", resolver=PUBLIC)
assert ok is True, reason
def test_cloud_metadata_blocked_even_when_private_allowed():
# The headline SSRF vector must be blocked regardless of block_private.
ok, reason = check_outbound_url("http://evil.example/latest/meta-data/", resolver=METADATA)
assert ok is False
assert "link-local" in reason
def test_ipv4_mapped_metadata_blocked():
ok, reason = check_outbound_url("http://evil6.example/", resolver=MAPPED_METADATA)
assert ok is False
assert "link-local" in reason
def test_loopback_and_lan_allowed_by_default_local_first():
# Local-first: a localhost / LAN embedding server is a legitimate target.
assert check_outbound_url("http://localhost:8080/v1", resolver=LOOPBACK)[0] is True
assert check_outbound_url("http://nas.local:1234/v1", resolver=LAN)[0] is True
def test_strict_mode_blocks_private_and_loopback():
ok, reason = check_outbound_url("http://localhost:8080", block_private=True, resolver=LOOPBACK)
assert ok is False and "private" in reason
ok, reason = check_outbound_url("http://nas.local", block_private=True, resolver=LAN)
assert ok is False and "private" in reason
def test_strict_mode_blocks_cgnat_shared_space():
# RFC 6598 shared/CGNAT space (100.64.0.0/10) is not globally routable.
# A public redirect into it must be rejected under full SSRF lockdown,
# even though ipaddress reports is_private=False for this range.
CGNAT = _resolver({"svc.example": ["100.64.0.1"]})
ok, reason = check_outbound_url("http://svc.example:8080", block_private=True, resolver=CGNAT)
assert ok is False
assert "blocked" in reason
def test_strict_mode_blocks_non_global_ranges():
# Strict mode is a full SSRF lockdown: only globally-routable public
# addresses may be reached. Benchmarking (198.18.0.0/15) and TEST-NET
# documentation space (192.0.2.0/24) are not globally routable.
for ip in ("198.18.0.1", "192.0.2.10"):
res = _resolver({"svc.example": [ip]})
ok, reason = check_outbound_url("http://svc.example", block_private=True, resolver=res)
assert ok is False, ip
assert "blocked" in reason
def test_strict_mode_still_allows_public_ip():
# The lockdown must not reject a legitimate globally-routable target.
ok, reason = check_outbound_url("https://example.com/v1", block_private=True, resolver=PUBLIC)
assert ok is True, reason
def test_unresolvable_host_blocked():
ok, reason = check_outbound_url("http://does-not-resolve.invalid", resolver=PUBLIC)
assert ok is False
assert "resolve" in reason
def test_resolver_values_must_include_a_parseable_ip():
ok, reason = check_outbound_url(
"https://example.test",
resolver=lambda _host: [None, 123, "not-an-ip"],
)
assert ok is False
assert "does not resolve to an IP" in reason
def test_resolver_skips_invalid_values_but_accepts_public_ip():
ok, reason = check_outbound_url(
"https://example.test",
resolver=lambda _host: [None, "not-an-ip", "93.184.216.34"],
)
assert ok is True
assert reason == "ok"