Questions tagged [attacks]
attempts by malicious users or software to subvert/manipulate the behaviour of an application or network
106
questions
0
votes
1answer
18 views
Flash loan price manipulation
I am quite new to flash loan and I don't fully understand it. I've been reading on flash loan attacks lately and notice often times it involves a huge dump on Uniswap to skew the price of a coin. I am ...
0
votes
0answers
5 views
How critical is timing to the Proof of Stake system?
I’m imagining that in the future it may be profitable for attackers to try to undermine consensus using novel means that are yet unanticipated. So I would like to contribute to speculation on possible ...
8
votes
2answers
113 views
Commit-Reveal contract still vulnerable to front running. How can it be improved?
I'm writing a contract and I want to shield it from front-running as best as it can possible be done (obviously, fully preventing front running would be ideal). My implementation is very similar to ...
0
votes
1answer
13 views
How does the oracle judge whether the request has been attacked by a man in the middle
The oracle machine can initiate a request to the data source whose URL is the HTTP link address. How does the oracle machine determine whether the HTTP request has been attacked by a man-in-the-middle,...
2
votes
1answer
47 views
how do we use `commit/reveal` to count votes?
Let's say we are doing an election and it's easy to note that we need commit/reveal scheme to hide votes.
So, we store hashes while users commit their votes. Now, let's say the election is over. How ...
1
vote
3answers
122 views
how does commit/reveal solve front-running?
I am trying to make sure I understand something correctly, so I will pose a problem with a solution.
Problem:
Let's say commit has been called. After this, we call the reveal. attacker listens to ...
0
votes
2answers
65 views
how can we stop front running for `approve` [duplicate]
function approve(address _spender, uint256 _value) returns (bool success)
This is the ordinary ERC20 approval method. It's easy to figure out that we have a problem of front-running.
Alice gives ...
0
votes
0answers
9 views
Using a partial network to evaluate low-cost smart contract
Suppose a smart contracts settles a bet/transaction concerning a total value of 0.2*(the minimum Ethereum transaction fee).
Do there exist protocols/smart contracts that allow the transaction to be ...
0
votes
1answer
30 views
question about smart contract code possible vulnerability
I need help with one of my smart contracts. I wrote a smart contract that have functions that only emit events. The parameters of each event are some of the functions parameters. I want to ask if ...
1
vote
1answer
17 views
can we jam the ETH network with assert/require functions?
If we make for example a smart contract with a require function that is always false and we execute it tons of times (knowing that we will get our gas back cause of the revert function)will we be able ...
1
vote
0answers
86 views
Flash minting ether security considerations and attacks
Flash loans enable a class of attacks that have not been possible or observed as much in prior systems.
Flash minting ether is a concept that is starting to be implemented.
See Example of flash ...
8
votes
4answers
764 views
Flash loan security considerations and attacks
What do developers need to be aware of to make their contracts and systems safe against flash loans?
What do they have to think about and protect against?
2
votes
0answers
831 views
Frontrunning Uniswap horror story transactions
From the Ethereum is a Dark Forest post, the rescue plan was:
Deploy a Getter contract which, when called by its owner, would make
the burn call ONLY if activated, and otherwise revert.
Deploy a ...
0
votes
0answers
14 views
How did Ethereum prevent 51% attack in the initial stage?
As far as I've known, Ethereum used Proof of Work as its consensus protocol. In the initial stage, the hash power of the Ethereum Network was small, so how Ethereum prevented 51% attack at that time?
2
votes
1answer
36 views
Is the May 2017 contract creation attack still possible?
In May 2017, an "attacker" created a contract that attempts to create many other contracts(using many JUMPDEST operations in the creation bytecode) until it runs out of gas.
I see the gas ...
0
votes
0answers
15 views
Whats prevents malicious node to spam the network with invalid transactions or invalid blocks?
Every peer of the malicious node will validate the transactions and or the block to confirm it is invalid. They won`t propagate it to the network but it still consumes bandwith and computing power. So ...
0
votes
1answer
30 views
DaoAttack not working
I am trying to replicate the famous DAO attack for a cryptocurrencies course.
I have the following contract already deployed on the blockchain.
pragma solidity ^0.5.4;
contract EDao {
address ...
0
votes
1answer
53 views
Integrity of old blocks in the blockchain
I am learning Ethereum using Geth, and I am testing PoA-Clique networks. Now I have a conceptual doubt about old blocks integrity. Suppose I have a private blockchain network of only one miner node ...
0
votes
1answer
38 views
Transaction Timing Implications for Reentry Attacks
This is the classic reentry attack:
function withdrawBalance() public {
uint amountToWithdraw = userBalances[msg.sender];
(bool success, ) = msg.sender.call.value(amountToWithdraw)("");
...
1
vote
1answer
57 views
Risk of Messages Not Having a Signature
As per my understanding transactions are signed before sending to Ethereum. Else, no transfer of Ether will happen. However, messages sent to Smart Contracts (SC) aren't signed (e.g., using methods....
4
votes
1answer
339 views
What is the “pre-commit” scheme to defeat frontrunning attack?
I am writing to inquire feasible strategies to defeat Transaction Ordering Dependence (TOD) bugs.
I learned from the best practice guideline such that we can use a so-called "pre-committed" scheme ...
0
votes
1answer
214 views
Griefing Attacks: Are they profitable for the attacker?
The following article explains one of the solutions for indirectly validate a block when cross-sharding transaction between two shards to prevent invalid blocks.
The article called one of these ...
1
vote
1answer
65 views
adaptive vs. non-adaptive adversaries? Is there a precise, unique and general definition? (Updated)
In this Ethereum github page (Link to the page: https://github.com/ethereum/wiki/wiki/Sharding-FAQ#what-are-the-security-models-that-we-are-operating-under) there is a very brief definition of the ...
2
votes
1answer
41 views
Would a 51% attack be easier if an attacker can DoS certain nodes?
I am wondering whether a 51% attack would be simplified by being able to remotely crash miner nodes. Consider the following scenario:
Malicious mining pool A controls 16% percent of the mining power ...
3
votes
1answer
51 views
Understand the trending of newly-uploaded smart contracts that is considered as vulnerable
We tried to use Oyente to analyze some online contracts and drawed a diagram regarding the potentially vulnerable smart contracts ("reentrancy" bug) with respect to their creation time.
So the y-...
0
votes
2answers
141 views
Create two contracts that each with different accounts.
I'm a newbie in blockchain. I am trying to repeat DAO attack using two different contracts, in my case DAO and Hacker. I want the 2 contracts belongs to 2 separated account, so I can see that the ...
0
votes
1answer
101 views
What is the work of self destruct in a contract?
How it can be used for handling force sending of ether to a contract without triggering fallback function ?
0
votes
0answers
102 views
A couple of questions on the Short Address attack
I have a few questions on the Short Address attack:
Is it possible to apply this attack on a function which does not take encoded byte-code as input and execute it, for example - function func(bytes ...
4
votes
1answer
114 views
Did DAO attacker gained ETH on Ethereum Classic?
I'm starting to study blockchain's world and the DAO attack caught my attention.
I studied how it worked and the solution proposed by the Ethereum community.
The hard fork splitted the blockchain in ...
3
votes
0answers
197 views
Denial attacks by submitting transactions with strategically calculated gas prices
As can be understood from the title, there is a specific form of denial attack where specific transactions are blocked by submitting transactions with strategically calculated gas prices.
Example 1: ...
1
vote
1answer
321 views
How does the exploit in FOMO3D work?
With the recent release of the FOMO3D exploit in its smart contract, how does the exploit work?
1
vote
1answer
78 views
Account management risks of booting into Tails OS from USB using a “partially air-gapped” Linux PC
My threat tolerance is around a 3 out of 5 on the paranoia scale. What are the practical account management risks of using a flash drive loaded with Tails OS to boot into a Linux PC, which will only ...
2
votes
3answers
162 views
Are Ethereum Contracts Vulnerable to Hash Table Poisoning Attacks?
Does anybody know something about this? I know that in general terms we will say not, but looking on the internet I found that isn't sure the answer to the question:
Can the EVM’s Internal ...
1
vote
1answer
46 views
Is it possible to use low mining complexity to remove some certain transaction in the past?
I have a question that has concerned me for a long time. It relates to the security and reliability of the blockchain applications.
Let's assume I want to build an application that uses Ethereum or ...
4
votes
1answer
293 views
ERC20 transfer - caller expects return but none provided - what happens?
If someone implements the ERC20 transfer() function without the return value as follows:
function transfer(address to, uint256 value) public {
require( ... usual checks ... );
balances_[msg....
2
votes
0answers
162 views
Who created this alt-Ropsten blockchain and why?
I usually test on Rinkeby, but this week I have to test some mining stuff, so I tried to get synced up with Ropsten. Unfortunately, after 3 days of trying, I still haven't had any success. The main ...
1
vote
1answer
366 views
Best practices for a secure Ethereum private network? [closed]
What are the best practices for an Ethereum private network with n nodes (programmed with Geth), to be secure from possibles external attacks?
I mean, which config parameters are recommended during ...
1
vote
1answer
264 views
What is the Eclipse attack and how was it fixed in Ethereum?
In this paper the researchers describe the Eclipse attack https://eprint.iacr.org/2015/263.pdf. Can someone explain it briefly, what steps an attacker needs to take to perform the attack and how it ...
6
votes
2answers
837 views
How does the 'secret chain' catch up with the real chain in the long range attack?
I'm trying to dig deep into Casper and one of the things that keep coming up is the long-range attack in PoS. I understand the attack at a high level - basically you would go back some large amount of ...
5
votes
3answers
1k views
Dealing with the short address attack
I'm writing a contract for an ERC20 token, based on Zepellin contracts. I noticed that their code doesn't handle the short address attack. Does it mean I shouldn't care about it?
1
vote
0answers
20 views
Why an attacker needs ~2^128 computing power to spoof membership of a key/value pair in a trie?
Ethereum Wiki:
Every unique set of key/value pairs maps uniquely to a root hash, and
it is not possible to spoof membership of a key/value pair in a trie
(unless an attacker has ~2^128 ...
0
votes
1answer
47 views
Leverage short positions in decentralised PoW currencies
Hint
I asked this question in a similar style already on bitcointalk and on bitcoin.stackexchange. But in these threads, there are no good answers and I thought maybe it would be better to ask the ...
1
vote
1answer
212 views
Unable to replicate short-address attack
I was reading about the short address attack and decided to replicate and test the possible solutions.
What I know about short address attack is if you skip n characters of your address, you end up ...
0
votes
1answer
385 views
What are the most common attack patterns on a Smart Contract? [duplicate]
i'm new to Solidity.
After writing my first smart contract im fairly concerned about it's security, once deployed to the MainNet. What are the most important things i should check within my code? ...
6
votes
2answers
738 views
Is sending some datas in the data field safe?
An airdrop ask to send it 0ETH with 150000 GAS and some datas in DATA field.
Is it safe?
What could be the aim of this transaction?
Thanks.
5
votes
1answer
119 views
Plasma.io: What if someone is offline during a mass withdrawal?
I'm reading the Plasma paper published a couple months ago, and on page 27, they talk about "Adversarial Mass Withdrawals" in the event of block withholding.
My question is, what if someone is ...
3
votes
1answer
2k views
Is it Safe to Share the Wallet Keystore File Without Password?
There is an ICO that asks for ethereum keystore file, which is unusual for me as far as ICOs go. Even though it does not looks like it contains private key and password it still feels unsettling.
Is ...
2
votes
3answers
445 views
In ethereum, what happen if someone controls a large majority of mining power?
If someone manages more than 50% of the mining power, this situation necessarily compromises the integrity of the past blocks and newly generating blocks?
1
vote
2answers
573 views
What if a malicious party sends two transactions with same nonce?
It's said nonce is used to prevent reply/double-spending attack. But an adversary can send two transactions with the same nonce, and the rest of scenario will be the same as in Bitcoin.
Question 1: ...
4
votes
1answer
119 views
Can an Ethereum key generated on a laptop be brute-forced by someone else because of low entropy?
I read this and this tweets. Though, I understand that this issue occur because some people use the same private key mentioned in a blog/forum.
But, on the first tweet, people were talking about the ...
