# Blockchain protocols

This classification applies to vulnerabilities that affect the core blockchain protocol or node-level consensus/security.

| **Severity**    | **Example Vulnerabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 🔴 **Critical** | <p>- <strong>Direct theft of funds</strong> (e.g., ledger corruption, consensus manipulation)<br>- <strong>Permanent freezing of funds</strong> (irrecoverable protocol-level lock)<br>- <strong>Total network shutdown</strong><br>    - Network unable to confirm transactions<br>    - Resolution requires a <strong>hard fork</strong><br><strong>- Consensus Manipulation or Fork Creation</strong>: Beyond shutdown, include the risk of chain split or invalid blocks.</p> |
| 🟠 **High**     | <p>- <strong>Application-level Denial of Service (DoS)</strong><br>    - Causes any node to crash under specific payloads or conditions<br>    - Attack can be mitigated via firewall rules<br>- <strong>Temporary freezing of network transactions</strong><br>- <strong>Temporary freezing of funds</strong> (e.g., liveness failure)</p>                                                                                                                                       |
| 🟡 **Medium**   | <p>- <strong>Application-level DoS</strong> affecting <strong>a subset of nodes</strong> (non-catastrophic)<br>- <strong>Unintended smart contract behavior</strong> due to protocol quirks or edge-case consensus rules<br>- <strong>Time Manipulation Attacks</strong>: Exploiting timestamp dependencies in consensus or smart contract behavior.<br>- <strong>Block Reorg Exploits</strong>: Minor reorganizations that can affect specific dApps or applications.</p>        |
| 🟢 **Low**      | <p>- <strong>Shutdown of <25% of network nodes</strong> (non-critical, no brute-force)<br>- <strong>Transaction fee modification or miscalculation</strong> without economic impact<br>- <strong>P2P Gossip Layer Issues</strong>: e.g., propagation delays, non-malicious message flooding, etc.</p>                                                                                                                                                                             |

If the issue is not under one of the mentioned vulnerabilities, we use the [Common Vulnerability Scoring System](http://159.89.29.143/redirect?url=https://www.first.org/cvss/user-guide) to assess the severity of your vulnerability.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hackenproof.com/bug-bounty/vulnerability-classification/blockchain-protocols.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.