nyx/src/dynamic/corpus/xxe/python.rs
2026-05-21 14:35:42 -05:00

98 lines
4.1 KiB
Rust

//! Python `Cap::XXE` payloads — `lxml.etree.XMLParser(resolve_entities=True)`.
//!
//! Vuln payload: an XML document declaring an external entity that
//! the harness's instrumented parser (`resolve_entities=True`)
//! expands inside `<data>`; the shim writes
//! `ProbeKind::Xxe { entity_expanded: true }` once it sees the entity
//! body substitute into the parsed tree.
//!
//! Benign control: a well-formed XML document with no doctype, so the
//! parser has nothing to resolve and the shim writes
//! `entity_expanded: false`.
//!
//! OOB-nonce variant (added 2026-05-21): when the runner attaches an
//! [`crate::dynamic::oob::OobListener`], the runner materialises this
//! payload's bytes as a loopback URL and the Python harness wraps the
//! URL into `<!ENTITY xxe SYSTEM "URL">`. Expat's external-entity hook
//! performs a real `urllib.request.urlopen` against the URL so the
//! listener records the per-finding nonce. Ordered first so the runner
//! exercises the OOB observation path before the doctype-entity vuln
//! triggers and short-circuits the iteration; runs without a listener
//! skip cleanly (the runner's `oob_nonce_slot` branch `continue`s when
//! [`crate::dynamic::sandbox::SandboxOptions::oob_listener`] is None).
use super::super::{CuratedPayload, Oracle, PayloadProvenance, PayloadRef};
use crate::dynamic::oracle::ProbePredicate;
pub const PAYLOADS: &[CuratedPayload] = &[
// OOB-nonce XXE variant. Ordered first so the harness exercises the
// OOB observation path before the doctype-entity vuln below triggers
// and breaks iteration. Self-confirming via [`Oracle::OobCallback`];
// no paired benign control because a benign URL can never hit the
// per-finding nonce path. Runs only when an [`OobListener`] is
// attached; the runner's `oob_nonce_slot` branch skips otherwise.
CuratedPayload {
bytes: b"",
label: "xxe-python-oob-nonce",
oracle: Oracle::OobCallback { host: "127.0.0.1" },
is_benign: false,
provenance: PayloadProvenance::Curated,
since_corpus_version: 15,
deprecated_at_corpus_version: None,
fixture_paths: &["tests/dynamic_fixtures/xxe/python/vuln.py"],
oob_nonce_slot: true,
probe_predicates: &[],
benign_control: None,
no_benign_control_rationale: Some(
"OOB-nonce XXE payload self-confirms via the per-finding listener \
callback when expat's external-entity hook fetches the loopback \
URL; no benign URL can hit the nonce path so no paired control \
is meaningful.",
),
},
CuratedPayload {
bytes: br#"<?xml version="1.0"?>
<!DOCTYPE data [
<!ENTITY xxe SYSTEM "file:///etc/hostname">
]>
<data>&xxe;</data>"#,
label: "xxe-python-doctype-entity",
oracle: Oracle::SinkProbe {
predicates: &[ProbePredicate::XxeEntityExpanded {
require_expanded: true,
}],
},
is_benign: false,
provenance: PayloadProvenance::Curated,
since_corpus_version: 9,
deprecated_at_corpus_version: None,
fixture_paths: &["tests/dynamic_fixtures/xxe/python/vuln.py"],
oob_nonce_slot: false,
probe_predicates: &[ProbePredicate::XxeEntityExpanded {
require_expanded: true,
}],
benign_control: Some(PayloadRef {
label: "xxe-python-benign",
}),
no_benign_control_rationale: None,
},
CuratedPayload {
bytes: br#"<?xml version="1.0"?>
<data>hello</data>"#,
label: "xxe-python-benign",
oracle: Oracle::SinkProbe {
predicates: &[ProbePredicate::XxeEntityExpanded {
require_expanded: true,
}],
},
is_benign: true,
provenance: PayloadProvenance::Curated,
since_corpus_version: 9,
deprecated_at_corpus_version: None,
fixture_paths: &["tests/dynamic_fixtures/xxe/python/benign.py"],
oob_nonce_slot: false,
probe_predicates: &[],
benign_control: None,
no_benign_control_rationale: None,
},
];