ENS’s codebase can be found at https://github.com/orgs/ensdomains/repositories. Documentation and further resources can be found on https://docs.ens.domains.

The Ethereum Name Service (ENS) is a distributed, open, and extensible naming system based on the Ethereum blockchain.

Taking over broken or expired outgoing links, such as:  Social media handles, etc.

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

Theft of registration fee

Permanent freezing of registration fees

Temporary freezing of funds

Temporary freezing of NFTs

Changing NFT metadata

Injecting/modifying the static content on the target application without JavaScript (persistent), such as:  HTML injection without JavaScript, Replacing existing text with arbitrary text, Arbitrary file uploads, etc

Improperly disclosing confidential user information, such as:  Email address, Phone number, Physical address, etc.

Subdomain takeover without already-connected wallet interaction

Redirecting users to malicious websites (open redirect)

Changing details of other users (including modifying browser local storage) without already-connected wallet interaction and with significant user interaction, such as: Iframing leading to modifying the backend/browser state (demonstrate impact with PoC)

Smart contract unable to operate due to lack of token funds

Block stuffing

Griefing (e.g. no profit motive for an attacker, but damage to the users or the protocol)

Theft of gas

Unbounded gas consumption

Taking down the application/website

Taking down the NFT URI

Changing non-sensitive details of other users (including modifying browser local storage) without already-connected wallet interaction and with up to one click of user interaction, such as:  Changing the name of user, Enabling/disabling notifications

Injecting/modifying the static content on the target application without JavaScript (reflected), such as:  Reflected HTML injection, Loading external site data

Manipulation of governance voting result deviating from voted outcome and resulting in a direct change from intended effect of original results

Direct theft of any user funds, whether at-rest or in-motion, other than unclaimed yield

Direct theft of any user NFTs, whether at-rest or in-motion, other than unclaimed royalties

Permanent freezing of funds

Permanent freezing of NFTs

Unauthorized minting of NFTs

Predictable or manipulable RNG that results in abuse of the principal or NFT

Unintended alteration of what the NFT represents (e.g. token URI, payload, artistic content)

Protocol insolvency

Theft of treasury funds

Permanent freezing of treasury funds

Execute arbitrary system commands

Retrieve sensitive data/files from a running server, such as:   Access tokens

Taking state-modifying authenticated actions (with or without blockchain state interaction) on behalf of other users without any interaction by that user, such as:   Changing registration information, Voting, Changing ENS records

Subdomain takeover with already-connected wallet interaction

Direct theft of user funds

Malicious interactions with an already-connected wallet, such as:  Modifying transaction arguments or parameters, Substituting contract addresses, Submitting malicious transactions

Direct theft of user NFTs

Injection of malicious HTML or XSS through metadata

Changing sensitive details of transactions (including modifying browser local storage) without already-connected wallet interaction and with up to one click of user interaction, such as: Registration Timer, Cached Transaction History

ENS Codebase

ENS Documentation

Rewards are broadly based on the principles set forth within the [Immunefi Vulnerability Severity Classification System V2.3. ](https://immunefi.com/immunefi-vulnerability-severity-classification-system-v2-3/)

For the sake of clarity, in the event of a conflict between that classification system and the rewards schema set forth below, the below language will control. 

__Reward Calculation for Critical Level Reports__

For critical smart contract bugs, the reward amount is 10% of the funds directly affected up to a maximum of USD 250 000. The calculation of the amount of funds at risk is based on the time and date the bug report is submitted. However, a minimum reward of USD 150 000 is to be rewarded in order to incentivize security researchers against withholding a critical bug report.

The reward for critical smart contract bugs on testnet assets ranges between USD 150 000 and USD 250 000, contingent upon the ability to calculate the funds impacted. In cases where objective calculation is not feasible, the minimum reward for testnet will be USD 150 000.


__Repeatable Attack Limitations__

If the smart contract where the vulnerability exists can be upgraded or paused, only the initial attacks within the first hour will be considered for a reward. This is because the project can mitigate the risk of further exploitation by upgrading or pausing the component where the vulnerability exists. The reward amount will depend on the severity of the impact and the funds at risk. 

For critical repeatable attacks on smart contracts that cannot be upgraded or paused, the project will consider the cumulative impact of the repeatable attacks for a reward. This is because the project cannot prevent the attacker from repeatedly exploiting the vulnerability until all funds are drained and/or other irreversible damage is done. Therefore, this warrants a reward equivalent to 10% of funds at risk, capped at the maximum critical reward. 

__Reward Calculation for High Level Reports__

High vulnerabilities concerning theft/permanent freezing of unclaimed yield/royalties are considered at the full amount of funds at risk, capped at the maximum high reward. This is to incentivize security researchers to uncover and responsibly disclose vulnerabilities that may have not have significant monetary value today, but could still be damaging to the project if it goes unaddressed.   

In the event of temporary freezing, the reward increases at a multiplier of two from the full frozen value for every additional 24h that the funds are temporarily frozen, up until a max cap of the high reward. This is because as the duration of the freezing lengthens, the potential for greater damage and subsequent reputational harm intensifies. Thus, by increasing the reward proportionally with the frozen duration, the project ensures stronger incentives for bug disclosure of this nature.    


For high smart contract bugs on testnet assets, the reward ranges between USD 100 000 to USD 150 000, contingent upon the ability to calculate the funds impacted. In cases where objective calculation is not feasible, the minimum reward for testnet will be USD 100 000.

For critical web/apps bug reports will be rewarded with USD 50 000, only if the impact leads to:

- A loss of funds involving an attack that does not require any user action
- Unauthorized minting of tokens on-chain
- Private key or private key generation leakage leading to unauthorized access to user funds 
- The impact occurs on a user facing application, generally hosted under ens.domains

All other impacts that would be classified as Critical would be rewarded a flat amount of USD 30 000. 

For high web/app impacts, the maximum reward of USD 20 000 will only be paid out for issues that affect our main user-facing applications, generally hosted under ens.domains. 

The rest of the severity levels are paid according to the Impact in Scope table.  

__Reward Payment Terms__

Payouts are handled by the ENS team directly and are denominated in USD. However, payments are done in USDC.

The calculation of the net amount rewarded is based on the average price between CoinMarketCap.com and CoinGecko.com at the time the bug report was submitted. No adjustments are made based on liquidity availability.