Bug bounty program
Triaged by HackenProof

The Flipcash Reserve Contract Bug Bounty: Program info

The Flipcash Reserve Contract Bug Bounty

Company: Flipcash
50 reputation points required POC required
Ended
Program left 76 days ago
Program infoHackers (69)Reports

Flipcash is a new platform for creating digital currencies. There are many things that make Flipcash unique, but one of the key differences is that every currency has guaranteed USD liquidity from day one. This guaranteed liquidity is managed by the Reserve Contract.

In scope
TargetTypeSeverity
https://github.com/code-payments/flipcash-program
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Smart Contract
Critical
https://explorer.solana.com/address/9oREdQzzrVH9HPTqKtVMbwP7fFtjrxVAYkMM664CwMGS
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Smart Contract
Critical
Target
https://github.com/code-payments/flipcash-program
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TypeSmart Contract
Severity
Critical
Target
https://explorer.solana.com/address/9oREdQzzrVH9HPTqKtVMbwP7fFtjrxVAYkMM664CwMGS
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TypeSmart Contract
Severity
Critical

Focus Area

IN SCOPE VULNERABILITIES (WEB, MOBILE)

We are interested in the following vulnerabilities:

  • Business logic issues
  • Payments manipulation
  • Remote code execution (RCE)
  • Injection vulnerabilities (SQL, XXE)
  • File inclusions (Local & Remote)
  • Access Control Issues (IDOR, Privilege Escalation, etc)
  • Leakage of sensitive information
  • Server-Side Request Forgery (SSRF)
  • Cross-Site Request Forgery (CSRF)
  • Cross-Site Scripting (XSS)
  • Directory traversal
  • Other vulnerabilities with a clear potential loss

OUT OF SCOPE: WEB VULNERABILITIES

Vulnerabilities found in out of scope resources are unlikely to be rewarded unless they present a serious business risk (at our sole discretion). In general, the following vulnerabilities do not correspond to the severity threshold:

  • Vulnerabilities in third-party applications
  • Assets that do not belong to the company
  • Best practices concerns
  • Recently (less than 30 days) disclosed 0day vulnerabilities
  • Vulnerabilities affecting users of outdated browsers or platforms
  • Social engineering, phishing, physical, or other fraud activities
  • Publicly accessible login panels without proof of exploitation
  • Reports that state that software is out of date/vulnerable without a proof of concept
  • Reports generated by scanners or any automated or active exploit tools
  • Vulnerabilities involving active content such as web browser add-ons
  • Most brute-forcing issues without clear impact
  • Denial of service (DoS/DDoS)
  • Theoretical issues
  • Moderately Sensitive Information Disclosure
  • Spam (sms, email, etc)
  • Missing HTTP security headers
  • Infrastructure vulnerabilities, including:
    • Certificates/TLS/SSL-related issues;
    • DNS issues (i.e. MX records, SPF records, DMARC records etc.);
    • Server configuration issues (i.e., open ports, TLS, etc.)
  • Open redirects
  • Session fixation
  • User account enumeration
  • Clickjacking/Tapjacking and issues only exploitable through clickjacking/tapjacking
  • Descriptive error messages (e.g. Stack Traces, application or server errors)
  • Self-XSS that cannot be used to exploit other users
  • Login & Logout CSRF
  • Weak Captcha/Captcha Bypass
  • Lack of Secure and HTTPOnly cookie flags
  • Username/email enumeration via Login/Forgot Password Page error messages
  • CSRF in forms that are available to anonymous users (e.g. the contact form)
  • OPTIONS/TRACE HTTP method enabled
  • Host header issues without proof-of-concept demonstrating clear security impact
  • Content spoofing and text injection issues without showing an attack vector/without being able to modify HTML/CSS
  • Content Spoofing without embedded links/HTML
  • Reflected File Download (RFD)
  • Mixed HTTP Content
  • HTTPS Mixed Content Scripts
  • Manipulation with Password Reset Token
  • MitM and local attacks
  • Response manipulations without demonstration of system state change

IN SCOPE VULNERABILITIES (Blockchain Protocol)

The list is not limited to the following submissions, but it gives an overview of what issues we care about:

  • Stealing or loss of funds
  • Unauthorized transaction
  • Transaction manipulation
  • Price manipulation
  • Fee payment bypass
  • Balance manipulation
  • Violation of tokenomics
  • Privacy violation
  • Cryptographic flaws

OUT OF SCOPE VULNERABILITIES (Blockchain Protocol)

  • Network-level DoS

IN SCOPE VULNERABILITIES (Smart Contracts)

We are looking for evidence and reasons for incorrect behavior of the smart contract, which could cause unintended functionality:

  • Stealing or loss of funds
  • Unauthorized transaction
  • Transaction manipulation
  • Attacks on logic (behavior of the code is different from the business description)
  • Reentrancy
  • Reordering
  • Over and underflows

OUT OF SCOPE VULNERABILITIES (Smart Contracts)

  • Theoretical vulnerabilities without any proof or demonstration
  • Old compiler version
  • The compiler version is not locked
  • Vulnerabilities in imported contracts
  • Code style guide violations
  • Redundant code
  • Gas optimizations
  • Best practice issues
  • Vulnerabilities that can be exploited through front-run attacks only

Program Rules

  • Avoid using web application scanners for automatic vulnerability searching which generates massive traffic
  • Make every effort not to damage or restrict the availability of products, services, or infrastructure
  • Avoid compromising any personal data, interruption, or degradation of any service
  • Don’t access or modify other user data, localize all tests to your accounts
  • Perform testing only within the scope
  • Don’t exploit any DoS/DDoS vulnerabilities, social engineering attacks, or spam
  • Don’t spam forms or account creation flows using automated scanners
  • In case you find chain vulnerabilities we’ll pay only for vulnerability with the highest severity.
  • Don’t break any law and stay in the defined scope
  • Any details of found vulnerabilities must not be communicated to anyone who is not a HackenProof Team or an authorized employee of this Company without appropriate permission

Disclosure Guidelines

  • Do not discuss this program or any vulnerabilities (even resolved ones) outside of the program without express consent from the organization
  • No vulnerability disclosure, including partial is allowed for the moment.
  • Please do NOT publish/discuss bugs

Eligibility and Coordinated Disclosure

We are happy to thank everyone who submits valid reports which help us improve the security. However, only those that meet the following eligibility requirements may receive a monetary reward:

  • You must be the first reporter of a vulnerability.
  • The vulnerability must be a qualifying vulnerability
  • Any vulnerability found must be reported no later than 24 hours after discovery and exclusively through hackenproof.com
  • You must send a clear textual description of the report along with steps to reproduce the issue, include attachments such as screenshots or proof of concept code as necessary.
  • You must not be a former or current employee of us or one of its contractor.
  • ONLY USE the EMAIL under which you registered your HackenProof account (in case of violation, no bounty can be awarded)
  • Provide detailed but to-the point reproduction steps

The Challenge: Steal Our BigBeautifulBounty

Flipcash is offering $250,000 USD to the first researcher who can steal BigBeautifulBounty, a test currency created in Flipcash, from our autonomous on-chain Solana smart contract called the Reserve. Context and challenge details are provided below.

The Reserve Contract

Every Flipcash currency is governed by the Reserve contract, an on-chain contract that autonomously manages each currency’s supply and liquidity.

When a new currency is created, 21 million coins are minted and deposited into the Reserve contract. Each currency has a fixed supply of 21 million coins, so there will never be more.

The Reserve contract then sells coins to users on a predefined pricing curve, accepting payment in USDF, a fully backed 1:1 USD stablecoin managed in partnership with Coinbase. The Reserve contract sells the first coin for $0.01 of USDF. It then raises the price slightly and sells the next coin. The predefined pricing curve is gradual but exponential, with the price increasing by approximately one penny per coin for every $11,400 of coins purchased, until the final 21 millionth coin sells for $1 million.

The Reserve contract autonomously self-custodies the USDF it receives. It uses that USDF to also buy coins from users on the same pricing curve. In doing so, the Reserve contract acts as a guaranteed buyer and seller, ensuring continuous liquidity without relying on market makers, order books, or liquidity providers, all in a fully autonomous manner.

When users sell their coins to the Reserve contract, the Reserve contract sets aside 1% of the resulting USDF as a sell fee, paying the remaining 99% to the user. This discourages sandwich attacks.

As sell fees accumulate in the Reserve contract they can be burned at any time without authority, ensuring that these fees can always be burned. These burns are credited to Flipcash as a redemption, which becomes revenue for the protocol.

Over time, the Reserve contract could self-custody billions of dollars of value. Because the Reserve contract is autonomous and will ultimately be immutable, any vulnerability could have severe consequences for the integrity of the Reserves. We have worked hard to ensure the security of the contract, but we want to do everything we can. This is where we could use your help.

Challenge Details

We have created a test currency, called BigBeautifulBounty (BBB). You can find it live on-chain here. BBB is managed by our Reserve contract. If you are the first to do one of the following to BBB we will pay you $250,000 USD, subject to eligibility requirements below.

  1. Drain USDF from the Reserve contract, such that holders of BBB can no longer sell their coins to the Reserve contract for at least the expected amount of USDF (allowing for rounding tolerance of $0.01 USDF)

  2. Drain the non-circulating supply of BBB from the Reserve contract, such that users can no longer buy more BBB for a cost of no more than the expected amount of USDF (allowing for rounding tolerance of $0.01 USDF)

  3. Permanently stall the Reserve contract, such that there is no way for holders of BBB to either sell their BBB to the Reserve contract, or buy more BBB from the Reserve contract

The payout will only go to the first person to exploit BBB in one of these three ways, and be able to prove that they were the ones who exploited it first. Final validation and payout eligibility will be determined by Flipcash.

Things That Will Help You

  • You can find the repository here

  • You can reach out to us to get USDF, or swap USDC for USDF here

  • You can find example test cases that interact with the Reserve contract here

  • We have completed an independent audit of the Reserve contract with Sec3, which you can find here

Submission Eligibility

The first valid submission based on the transaction timestamp will get the reward.

To qualify you must steal BBB before March 31, 2026 (23:59 UTC)

Referral Bonus

We are offering an additional $50,000 USD to anyone who refers a researcher that submits a valid, payout-eligible finding. (The researcher must credit you in their submission).

Responsible Disclosure

To support responsible disclosure, we will not pursue legal action against researchers who follow this policy and act in good faith.

Note

Payment for a successful submission will be made in USDC. To remit payment, we must collect basic personal information.

As a US-based company, we cannot pay bounties to individuals residing in countries subject to U.S. trade restrictions or export sanctions, as determined by the Office of Foreign Assets Control (OFAC).

Flipcash reserves the right to update or modify the terms of this bounty. Changes will apply prospectively and will be reflected by the “Last Updated” date above.

Rewards
Range of bounty$0 - $250,000
Severity
Critical
$250,000
High
$0
Medium
$0
Low
$0
Stats
Scope Review19852
Submissions98
Total rewards$0
Types
smart contract
Languages
Rust
Platforms
Solana
SLA (Service Level Agreement)
Time within which the program's triage team must respond
Response TypeBusiness days
First Response3d
Triage Time3d
Reward Time3d
Resolution Time14d