Last Updated: 2026-03-18 Audit Version: 1.0

✅ Core Protocol: SECURE 🔴 Python Bindings: Requires Attention

Affected Component: pap-python crate (Python bindings) CVE: Not yet assigned CVSS Score: TBD (estimated 7.5 - HIGH)

Buffer overflow risk in PyString::from_object method in pyo3 versions < 0.24.1. This vulnerability affects the Python bindings only - the core Rust protocol implementation is NOT affected.

• Scope: Python bindings (pap-python) ONLY
• Core Protocol: ✅ NOT AFFECTED
• Rust Users: ✅ NOT AFFECTED
• Python Users: ✅ FIXED (pyo3 upgraded to 0.24+)

# COMPLETED - pap-python/Cargo.toml
[dependencies]
pyo3 = { version = "0.24", features = ["extension-module", "abi3-py38"] }

• Discovered: 2026-03-18 (via cargo-audit)
• Fixed: 2026-03-18 (pyo3 upgraded, all deprecations fixed)
• Status: ✅ RESOLVED
• Verification: cargo check --package pap-python - zero warnings

Affected Component: pap-transport, pap-federation (via reqwest) Severity: LOW

The rustls-pemfile dependency (used transitively via reqwest) is no longer actively maintained. No known exploits exist.

• No immediate security risk
• May lack future security patches

• Monitor for maintained replacement
• Consider updating reqwest to version that uses alternative
• Track: https://github.com/rustls/pemfile/issues

1. TLS Required: Always use HTTPS for pap-transport (PAP does not implement TLS)
2. Key Management: Store Ed25519 private keys securely (HSM, encrypted storage)
3. Nonce Tracking: Maintain persistent nonce consumed set to prevent replay attacks
4. Mandate Validation: Always verify mandate chains before trusting delegated agents
5. Audit Receipts: Regularly review transaction receipts for anomalies

1. Dependencies: Run cargo audit before releases
2. Testing: All crypto code has >90% test coverage
3. Fuzzing: Consider fuzzing signature verification and disclosure hashing
4. Code Review: All PRs require review for crypto changes
5. Static Analysis: CI enforces zero Clippy warnings

DO NOT open public GitHub issues for security vulnerabilities.

Email: security@baur.software PGP Key: (TODO: add PGP key)

Please include:

• Description of the vulnerability
• Steps to reproduce
• Potential impact assessment
• Suggested fix (if available)

• Acknowledgment: Within 48 hours
• Initial Assessment: Within 1 week
• Fix Development: Depends on severity (critical: <48h, high: <1 week)
• Public Disclosure: After fix is released (coordinated disclosure)

✅ Ed25519 Signature Verification: All mandates, tokens, receipts cryptographically signed ✅ Nonce Replay Prevention: Single-use tokens via nonce tracking ✅ Mandate Chain Integrity: Hash-linked, scope/TTL constraints enforced ✅ Selective Disclosure: SD-JWT with hash commitments (unlinkability) ✅ Receipt Immutability: Co-signed by both parties, append-only

❌ Transport Security: You must use HTTPS/TLS ❌ Key Storage: You must secure private keys ❌ Payment Anonymity: Relies on external ecash systems (Chaumian mints) ❌ DID Resolution: You must implement DID lookup (we only use did:key)

• Critical vulnerabilities: Patch within 48 hours
• High severity: Patch within 1 week
• Medium/Low severity: Include in next minor release
• Dependency updates: Monthly cargo update + audit

Security Team: security@baur.software General Issues: https://github.com/Baur-Software/pap/issues Audit Requests: Reach out via email for professional audits

This document is part of the Principal Agent Protocol (PAP) security documentation. For technical details, see AUDIT_REPORT.md