# 33277 - \[BC - Critical] Validators can be crashed via GET Submitted on Jul 17th 2024 at 03:26:00 UTC by @usmannk for [Boost | Shardeum: Core](https://immunefi.com/bounty/shardeum-core-boost/) Report ID: #33277 Report type: Blockchain/DLT Report severity: Critical Target: Impacts: * Network not being able to confirm new transactions (total network shutdown) ## Description ## Brief/Intro Simply calling the default endpoint `eth_getBlockByHash` **with no params** causes a node to crash and die permanently. By looping this over the network, an attacker can halt all transactions. ## Proof of Concept * Run a local cluster: * `$ shardus start 10` * Pick a node, say, 9001. * Crash the node by navigating to `http://localhost:9001/eth_getBlockByHash` and not providing parameters * Go to `http://127.0.0.1:4000/nodelist` and observe that the node is offline --- # 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://reports.immunefi.com/shardeum-core/33277-bc-critical-validators-can-be-crashed-via-get.md?ask= ``` 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.