software-data-integrity-failures

A08:2025 — Software or Data Integrity Failures

Overview

OWASP rank: #8 (2025) | CWEs covered: 14 | Avg incidence: 2.75%

This category focuses on failure to verify integrity of software, code, and data artifacts within your own environment — distinct from A03's upstream supply chain focus. The core concern is: can you trust what you're loading, deserializing, or executing?

Key distinction from A03 (Supply Chain):

• A03 = upstream integrity (your dependencies, CI/CD pipelines)
• A08 = runtime integrity (what you actually deserialize, include, or auto-update at runtime)

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Critical Risk Areas for Python

1. Insecure Deserialization — The #1 Python-Specific Risk

pickle.loads() on untrusted input equals arbitrary code execution via __reduce__. This is the single most dangerous A08 vector in Python.

Dangerous functions/modules to flag:

Module / Function	Risk	Safe Alternative
pickle.loads() / pickle.load()	RCE via __reduce__	JSON + Pydantic
cPickle.loads()	Same as pickle	JSON + Pydantic
dill.loads()	Superset of pickle, same RCE risk	JSON + Pydantic
jsonpickle.decode()	Deserializes Python objects	json.loads() only
shelve.open()	Backed by pickle	Redis/SQL store
yaml.load(data, Loader=None)	Code execution via !!python/object	yaml.safe_load()
numpy.load(f, allow_pickle=True)	RCE via pickled arrays	allow_pickle=False
torch.load(f)	Pickle-backed by default	weights_only=True

Detection pattern (static analysis):

# Flag any of these patterns in source code
DANGEROUS_PATTERNS = [
    r'pickle\.loads?\(',
    r'cPickle\.loads?\(',
    r'dill\.loads?\(',
    r'jsonpickle\.decode\(',
    r'shelve\.open\(',
    r'yaml\.load\([^)]*(?!safe_load)',
    r'numpy\.load\([^)]*allow_pickle\s*=\s*True',
    r'torch\.load\([^)]*(?!weights_only\s*=\s*True)',
]

If pickle is unavoidable — HMAC integrity check:

import hmac, hashlib, pickle, os

SECRET = os.environ["PICKLE_HMAC_SECRET"].encode()

def safe_serialize(obj) -> bytes:
    data = pickle.dumps(obj)
    mac = hmac.new(SECRET, data, hashlib.sha256).digest()
    return mac + data  # prepend 32-byte MAC

def safe_deserialize(payload: bytes):
    mac, data = payload[:32], payload[32:]
    expected = hmac.new(SECRET, data, hashlib.sha256).digest()
    if not hmac.compare_digest(mac, expected):
        raise ValueError("Integrity check failed — data tampered")
    return pickle.loads(data)