{
  "verdict": "no_bypass_found",
  "verdict_date": "2026-05-28T12:00:00Z",
  "explanation": "Three distinct variant attempts were systematically tested against both the vulnerable (v5.9.0-stable) and fixed (v5.9.1-stable) versions of wolfSSL. All attempts reproduced the underlying integrity failure on the vulnerable version and were correctly blocked by the fixed version. The original fix (commit 1d363f3a) adds explicit tag comparison in wolfSSL_EVP_CipherFinal for WC_CHACHA20_POLY1305_TYPE. No alternate entry point, API wrapper, or input encoding was found that bypasses the fix. The fix is complete for the reported vulnerability.",
  "variant_attempts": [
    {
      "attempt_id": 1,
      "description": "EVP_CipherInit streaming path with bad tag (QUIC-like API usage)",
      "vulnerable_result": "reproduced",
      "fixed_result": "blocked"
    },
    {
      "attempt_id": 2,
      "description": "Modified AAD with correct tag and ciphertext",
      "vulnerable_result": "reproduced",
      "fixed_result": "blocked"
    },
    {
      "attempt_id": 3,
      "description": "Flipped ciphertext byte with correct tag",
      "vulnerable_result": "reproduced",
      "fixed_result": "blocked"
    }
  ],
  "blocking_mitigation": "The fix in wolfSSL_EVP_CipherFinal saves the expected tag before wc_ChaCha20Poly1305_Final overwrites ctx->authTag, then compares expected vs computed using wc_ChaCha20Poly1305_CheckTag. This covers all callers because EVP_DecryptFinal_ex, EVP_CipherFinal, and EVP_CipherFinal_ex are macro aliases for wolfSSL_EVP_CipherFinal.",
  "tested_vulnerable_commit": "922d04b3568c6428a9fb905ddee3ef5a68db3108",
  "tested_fixed_commit": "1d363f3adceba9d1478230ede476a37b0dcdef24"
}