Teller

Teller is an algorithmic credit risk protocol, built to enable the creation of decentralized lending markets that can offer unsecured loans. The protocol’s unique cloud-based infrastructure can connect to, and privately compute credit and banking data to generate individual loan terms based on a users’ creditworthiness. Teller Protocol was designed to develop decentralized loan products, without collateralized debt, reducing consumer risk and costs. Teller can interoperate with centralized finance data, offering everyone the freedom to develop a new wealth of trustless financial instruments.

For more information about Teller, please visit https://www.teller.finance/.

The bug bounty program covers its smart contracts and app and is focused on preventing the following impacts:

• Thefts and freezing of principal of any amount
• Leak of user data
• Thefts and freezing of unclaimed yield of any amount

Rewards are distributed according to the impact of the vulnerability based on the Immunefi Vulnerability Severity Classification System. This is a simplified 5-level scale, with separate scales for websites/apps and smart contracts/blockchains, encompassing everything from consequence of exploitation to privilege required to likelihood of a successful exploit.

All web and app bugs must come with a PoC in order to be accepted. Additionally, all smart contract vulnerabilities that are Medium or higher are required to have a PoC for the consideration of a reward.

Payouts are handled by the Teller team directly and are denominated in USD. Payouts are done in ETH.

Only web/app vulnerabilities that directly affect the web/app assets listed in this table are accepted within the bug bounty program. All others are out-of-scope.

Impacts in Scope

Only the following impacts are accepted within this bug bounty program. All other impacts are not considered as in-scope, even if they affect something in the assets in scope table.

Smart Contracts

• Loss of user funds staked (principal) by freezing or theft
• Theft of unclaimed yield
• Freezing of unclaimed yield
• Temporary freezing of funds for any amount of time
• Unable to call smart contract

Web/App

• Leak of user data
• Redirected funds by address modification
• Users spoofing other users

We are especially interested in receiving and rewarding vulnerabilities of the following types:

Smart Contracts and Blockchain

• Re-entrancy
• Logic errors
  • including user authentication errors
• Solidity/EVM details not considered
  • including integer over-/under-flow
  • including rounding errors
  • including unhandled exceptions
• Trusting trust/dependency vulnerabilities
  • including composability vulnerabilities
• Oracle failure/manipulation
• Novel governance attacks
• Economic/financial attacks
  • including flash loan attacks
• Congestion and scalability
  • including running out of gas
  • including block stuffing
  • including susceptibility to frontrunning
• Consensus failures
• Cryptography problems
  • Signature malleability
  • Susceptibility to replay attacks
  • Weak randomness
  • Weak encryption
• Susceptibility to block timestamp manipulation
• Missing access controls / unprotected internal or debugging interfaces

Websites and Apps

• Remote Code Execution
• Trusting trust/dependency vulnerabilities
• Vertical Privilege Escalation
• XML External Entities Injection
• SQL Injection
• LFI/RFI
• Horizontal Privilege Escalation
• Stored XSS
• Reflective XSS with impact
• CSRF with impact
• Direct object reference
• Internal SSRF
• Session fixation
• Insecure Deserialization
• DOM XSS
• SSL misconfigurations
• SSL/TLS issues (weak crypto, improper setup)
• URL redirect
• Clickjacking (must be accompanied with PoC)
• Misleading Unicode text (e.g. using right to left override characters)

The following vulnerabilities are excluded from the rewards for this bug bounty program:

• Attacks that the reporter has already exploited themselves, leading to damage
• Attacks requiring access to leaked keys/credentials
• Attacks requiring access to privileged addresses (governance, strategist)

Smart Contracts and Blockchain

• Incorrect data supplied by third party oracles
  • Not to exclude oracle manipulation/flash loan attacks
• Basic economic governance attacks (e.g. 51% attack)
• Lack of liquidity
• Best practice critiques
• Sybil attacks

Websites and Apps

• Theoretical vulnerabilities without any proof or demonstration
• Content spoofing / Text injection issues
• Self-XSS
• Captcha bypass using OCR
• CSRF with no security impact (logout CSRF, change language, etc.)
• Missing HTTP Security Headers (such as X-FRAME-OPTIONS) or cookie security flags (such as “httponly”)
• Server-side information disclosure such as IPs, server names, and most stack traces
• Vulnerabilities used to enumerate or confirm the existence of users or tenants
• Vulnerabilities requiring unlikely user actions
• URL Redirects (unless combined with another vulnerability to produce a more severe vulnerability)
• Lack of SSL/TLS best practices
• DDoS vulnerabilities
• Attacks requiring privileged access from within the organization
• Feature requests
• Best practices

The following activities are prohibited by this bug bounty program:

• Any testing with mainnet or public testnet contracts; all testing should be done on private testnets
• Any testing with pricing oracles or third party smart contracts
• Attempting phishing or other social engineering attacks against our employees and/or customers
• Any testing with third party systems and applications (e.g. browser extensions) as well as websites (e.g. SSO providers, advertising networks)
• Any denial of service attacks
• Automated testing of services that generates significant amounts of traffic
• Public disclosure of an unpatched vulnerability in an embargoed bounty