HIGH severity: Mint Tokens. The contract owner has the authority to mint tokens, which can lead to highly inflated contract tokens.

Vulnerable code:
pragma solidity 0.5.16;

 

interface IBEP20 {

  /**

   * @dev Returns the amount of tokens in existence.

   */

  function totalSupply() external view returns (uint256);

 

  /**

   * @dev Returns the token decimals.

   */

  function decimals() external view returns (uint8);

 

  /**

   * @dev Returns the token symbol.

   */

  function symbol() external view returns (string memory);

 

  /**

  * @dev Returns the token name.

  */

  function name() external view returns (string memory);

 

  /**

   * @dev Returns the bep token owner.

   */

  function getOwner() external view returns (address);

 

  /**

   * @dev Returns the amount of tokens owned by `account`.

   */

  function balanceOf(address account) external view returns (uint256);

 

  /**

   * @dev Moves `amount` tokens from the caller's account to `recipient`.

   *

   * Returns a boolean value indicating whether the operation succeeded.

   *

   * Emits a {Transfer} event.

   */

  function transfer(address recipient, uint256 amount) external returns (bool);

 

  /**

   * @dev Returns the remaining number of tokens that `spender` will be

   * allowed to spend on behalf of `owner` through {transferFrom}. This is

   * zero by default.

   *

   * This value changes when {approve} or {transferFrom} are called.

   */

  function allowance(address _owner, address spender) external view returns (uint256);

 

  /**

   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.

   *

   * Returns a boolean value indicating whether the operation succeeded.

   *

   * IMPORTANT: Beware that changing an allowance with this method brings the risk

   * that someone may use both the old and the new allowance by unfortunate

   * transaction ordering. One possible solution to mitigate this race

   * condition is to first reduce the spender's allowance to 0 and set the

   * desired value afterwards:

   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729

   *

   * Emits an {Approval} event.

   */

  function approve(address spender, uint256 amount) external returns (bool);

 

  /**

   * @dev Moves `amount` tokens from `sender` to `recipient` using the

   * allowance mechanism. `amount` is then deducted from the caller's

   * allowance.

   *

   * Returns a boolean value indicating whether the operation succeeded.

   *

   * Emits a {Transfer} event.

   */

  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

 

  /**

   * @dev Emitted when `value` tokens are moved from one account (`from`) to

   * another (`to`).

   *

   * Note that `value` may be zero.

   */

  event Transfer(address indexed from, address indexed to, uint256 value);

 

  /**

   * @dev Emitted when the allowance of a `spender` for an `owner` is set by

   * a call to {approve}. `value` is the new allowance.

   */

  event Approval(address indexed owner, address indexed spender, uint256 value);

}

 

/*

 * @dev Provides information about the current execution context, including the

 * sender of the transaction and its data. While these are generally available

 * via msg.sender and msg.data, they should not be accessed in such a direct

 * manner, since when dealing with GSN meta-transactions the account sending and

 * paying for execution may not be the actual sender (as far as an application

 * is concerned).

 *

 * This contract is only required for intermediate, library-like contracts.

 */

contract Context {

  // Empty internal constructor, to prevent people from mistakenly deploying

  // an instance of this contract, which should be used via inheritance.

  constructor () internal { }

 

  function _msgSender() internal view returns (address payable) {

    return msg.sender;

  }

 

  function _msgData() internal view returns (bytes memory) {

    this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691

    return msg.data;

  }

}

 

/**

 * @dev Wrappers over Solidity's arithmetic operations with added overflow

 * checks.

 *

 * Arithmetic operations in Solidity wrap on overflow. This can easily result

 * in bugs, because programmers usually assume that an overflow raises an

 * error, which is the standard behavior in high level programming languages.

 * `SafeMath` restores this intuition by reverting the transaction when an

 * operation overflows.

 *

 * Using this library instead of the unchecked operations eliminates an entire

 * class of bugs, so it's recommended to use it always.

 */

library SafeMath {

  /**

   * @dev Returns the addition of two unsigned integers, reverting on

   * overflow.

   *

   * Counterpart to Solidity's `+` operator.

   *

   * Requirements:

   * - Addition cannot overflow.

   */

  function add(uint256 a, uint256 b) internal pure returns (uint256) {

    uint256 c = a + b;

    require(c >= a, "SafeMath: addition overflow");

 

    return c;

  }

 

  /**

   * @dev Returns the subtraction of two unsigned integers, reverting on

   * overflow (when the result is negative).

   *

   * Counterpart to Solidity's `-` operator.

   *

   * Requirements:

   * - Subtraction cannot overflow.

   */

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {

    return sub(a, b, "SafeMath: subtraction overflow");

  }

 

  /**

   * @dev Returns the subtraction of two unsigned integers, reverting with custom message on

   * overflow (when the result is negative).

   *

   * Counterpart to Solidity's `-` operator.

   *

   * Requirements:

   * - Subtraction cannot overflow.

   */

  function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {

    require(b <= a, errorMessage);

    uint256 c = a - b;

 

    return c;

  }

 

  /**

   * @dev Returns the multiplication of two unsigned integers, reverting on

   * overflow.

   *

   * Counterpart to Solidity's `*` operator.

   *

   * Requirements:

   * - Multiplication cannot overflow.

   */

  function mul(uint256 a, uint256 b) internal pure returns (uint256) {

    // Gas optimization: this is cheaper than requiring 'a' not being zero, but the

    // benefit is lost if 'b' is also tested.

    // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522

    if (a == 0) {

      return 0;

    }

 

    uint256 c = a * b;

    require(c / a == b, "SafeMath: multiplication overflow");

 

    return c;

  }

 

  /**

   * @dev Returns the integer division of two unsigned integers. Reverts on

   * division by zero. The result is rounded towards zero.

   *

   * Counterpart to Solidity's `/` operator. Note: this function uses a

   * `revert` opcode (which leaves remaining gas untouched) while Solidity

   * uses an invalid opcode to revert (consuming all remaining gas).

   *

   * Requirements:

   * - The divisor cannot be zero.

   */

  function div(uint256 a, uint256 b) internal pure returns (uint256) {

    return div(a, b, "SafeMath: division by zero");

  }

 

  /**

   * @dev Returns the integer division of two unsigned integers. Reverts with custom message on

   * division by zero. The result is rounded towards zero.

   *

   * Counterpart to Solidity's `/` operator. Note: this function uses a

   * `revert` opcode (which leaves remaining gas untouched) while Solidity

   * uses an invalid opcode to revert (consuming all remaining gas).

   *

   * Requirements:

   * - The divisor cannot be zero.

   */

  function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {

    // Solidity only automatically asserts when dividing by 0

    require(b > 0, errorMessage);

    uint256 c = a / b;

    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

 

    return c;

  }

 

  /**

   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),

   * Reverts when dividing by zero.

   *

   * Counterpart to Solidity's `%` operator. This function uses a `revert`

   * opcode (which leaves remaining gas untouched) while Solidity uses an

   * invalid opcode to revert (consuming all remaining gas).

   *

   * Requirements:

   * - The divisor cannot be zero.

   */

  function mod(uint256 a, uint256 b) internal pure returns (uint256) {

    return mod(a, b, "SafeMath: modulo by zero");

  }

 

  /**

   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),

   * Reverts with custom message when dividing by zero.

   *

   * Counterpart to Solidity's `%` operator. This function uses a `revert`

   * opcode (which leaves remaining gas untouched) while Solidity uses an

   * invalid opcode to revert (consuming all remaining gas).

   *

   * Requirements:

   * - The divisor cannot be zero.

   */

  function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {

    require(b != 0, errorMessage);

    return a % b;

  }

}

 

/**

 * @dev Contract module which provides a basic access control mechanism, where

 * there is an account (an owner) that can be granted exclusive access to

 * specific functions.

 *

 * By default, the owner account will be the one that deploys the contract. This

 * can later be changed with {transferOwnership}.

 *

 * This module is used through inheritance. It will make available the modifier

 * `onlyOwner`, which can be applied to your functions to restrict their use to

 * the owner.

 */

contract Ownable is Context {

  address private _owner;

 

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

 

  /**

   * @dev Initializes the contract setting the deployer as the initial owner.

   */

  constructor () internal {

    address msgSender = _msgSender();

    _owner = msgSender;

    emit OwnershipTransferred(address(0), msgSender);

  }

 

  /**

   * @dev Returns the address of the current owner.

   */

  function owner() public view returns (address) {

    return _owner;

  }

 

  /**

   * @dev Throws if called by any account other than the owner.

   */

  modifier onlyOwner() {

    require(_owner == _msgSender(), "Ownable: caller is not the owner");

    _;

  }

 

  /**

   * @dev Leaves the contract without owner. It will not be possible to call

   * `onlyOwner` functions anymore. Can only be called by the current owner.

   *

   * NOTE: Renouncing ownership will leave the contract without an owner,

   * thereby removing any functionality that is only available to the owner.

   */

  function renounceOwnership() public onlyOwner {

    emit OwnershipTransferred(_owner, address(0));

    _owner = address(0);

  }

 

  /**

   * @dev Transfers ownership of the contract to a new account (`newOwner`).

   * Can only be called by the current owner.

   */

  function transferOwnership(address newOwner) public onlyOwner {

    _transferOwnership(newOwner);

  }

 

  /**

   * @dev Transfers ownership of the contract to a new account (`newOwner`).

   */

  function _transferOwnership(address newOwner) internal {

    require(newOwner != address(0), "Ownable: new owner is the zero address");

    emit OwnershipTransferred(_owner, newOwner);

    _owner = newOwner;

  }

}

 

contract BRICS is Context, IBEP20, Ownable {

  using SafeMath for uint256;

 

  mapping (address => uint256) private _balances;

 

  mapping (address => mapping (address => uint256)) private _allowances;

 

  uint256 public _totalSupply;

  uint8 public _decimals;

  string public _symbol;

  string public _name;

 

  constructor() public {

    _name = "BRICS TOKEN";

    _symbol = "BRICS";

    _decimals = 18;

    _totalSupply = 1000000000000000000000000000;

    _balances[msg.sender] = _totalSupply;

 

    emit Transfer(address(0), msg.sender, _totalSupply);

  }

 

  /**

   * @dev Returns the bep token owner.

   */

  function getOwner() external view returns (address) {

    return owner();

  }

 

  /**

   * @dev Returns the token decimals.

   */

  function decimals() external view returns (uint8) {

    return _decimals;

  }

 

  /**

   * @dev Returns the token symbol.

   */

  function symbol() external view returns (string memory) {

    return _symbol;

  }

 

  /**

  * @dev Returns the token name.

  */

  function name() external view returns (string memory) {

    return _name;

  }

 

  /**

   * @dev See {BEP20-totalSupply}.

   */

  function totalSupply() external view returns (uint256) {

    return _totalSupply;

  }

 

  /**

   * @dev See {BEP20-balanceOf}.

   */

  function balanceOf(address account) external view returns (uint256) {

    return _balances[account];

  }

 

  /**

   * @dev See {BEP20-transfer}.

   *

   * Requirements:

   *

   * - `recipient` cannot be the zero address.

   * - the caller must have a balance of at least `amount`.

   */

  function transfer(address recipient, uint256 amount) external returns (bool) {

    _transfer(_msgSender(), recipient, amount);

    return true;

  }

 

  /**

   * @dev See {BEP20-allowance}.

   */

  function allowance(address owner, address spender) external view returns (uint256) {

    return _allowances[owner][spender];

  }

 

  /**

   * @dev See {BEP20-approve}.

   *

   * Requirements:

   *

   * - `spender` cannot be the zero address.

   */

  function approve(address spender, uint256 amount) external returns (bool) {

    _approve(_msgSender(), spender, amount);

    return true;

  }

 

  /**

   * @dev See {BEP20-transferFrom}.

   *

   * Emits an {Approval} event indicating the updated allowance. This is not

   * required by the EIP. See the note at the beginning of {BEP20};

   *

   * Requirements:

   * - `sender` and `recipient` cannot be the zero address.

   * - `sender` must have a balance of at least `amount`.

   * - the caller must have allowance for `sender`'s tokens of at least

   * `amount`.

   */

  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) {

    _transfer(sender, recipient, amount);

    _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "BEP20: transfer amount exceeds allowance"));

    return true;

  }

 

  /**

   * @dev Atomically increases the allowance granted to `spender` by the caller.

   *

   * This is an alternative to {approve} that can be used as a mitigation for

   * problems described in {BEP20-approve}.

   *

   * Emits an {Approval} event indicating the updated allowance.

   *

   * Requirements:

   *

   * - `spender` cannot be the zero address.

   */

  function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {

    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));

    return true;

  }

 

  /**

   * @dev Atomically decreases the allowance granted to `spender` by the caller.

   *

   * This is an alternative to {approve} that can be used as a mitigation for

   * problems described in {BEP20-approve}.

   *

   * Emits an {Approval} event indicating the updated allowance.

   *

   * Requirements:

   *

   * - `spender` cannot be the zero address.

   * - `spender` must have allowance for the caller of at least

   * `subtractedValue`.

   */

  function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {

    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "BEP20: decreased allowance below zero"));

    return true;

  }

 

  /**

   * @dev Creates `amount` tokens and assigns them to `msg.sender`, increasing

   * the total supply.

   *

   * Requirements

   *

   * - `msg.sender` must be the token owner

   */

  function mint(uint256 amount) public onlyOwner returns (bool) {

    _mint(_msgSender(), amount);

    return true;

  }

 

  /**

   * @dev Moves tokens `amount` from `sender` to `recipient`.

   *

   * This is internal function is equivalent to {transfer}, and can be used to

   * e.g. implement automatic token fees, slashing mechanisms, etc.

   *

   * Emits a {Transfer} event.

   *

   * Requirements:

   *

   * - `sender` cannot be the zero address.

   * - `recipient` cannot be the zero address.

   * - `sender` must have a balance of at least `amount`.

   */

  function _transfer(address sender, address recipient, uint256 amount) internal {

    require(sender != address(0), "BEP20: transfer from the zero address");

    require(recipient != address(0), "BEP20: transfer to the zero address");

 

    _balances[sender] = _balances[sender].sub(amount, "BEP20: transfer amount exceeds balance");

    _balances[recipient] = _balances[recipient].add(amount);

    emit Transfer(sender, recipient, amount);

  }

 

  /** @dev Creates `amount` tokens and assigns them to `account`, increasing

   * the total supply.

   *

   * Emits a {Transfer} event with `from` set to the zero address.

   *

   * Requirements

   *

   * - `to` cannot be the zero address.

   */

  function _mint(address account, uint256 amount) internal {

    require(account != address(0), "BEP20: mint to the zero address");

 

    _totalSupply = _totalSupply.add(amount);

    _balances[account] = _balances[account].add(amount);

    emit Transfer(address(0), account, amount);

  }

 

  /**

   * @dev Destroys `amount` tokens from `account`, reducing the

   * total supply.

   *

   * Emits a {Transfer} event with `to` set to the zero address.

   *

   * Requirements

   *

   * - `account` cannot be the zero address.

   * - `account` must have at least `amount` tokens.

   */

  function _burn(address account, uint256 amount) internal {

    require(account != address(0), "BEP20: burn from the zero address");

 

    _balances[account] = _balances[account].sub(amount, "BEP20: burn amount exceeds balance");

    _totalSupply = _totalSupply.sub(amount);

    emit Transfer(account, address(0), amount);

  }

 

  /**

   * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.

   *

   * This is internal function is equivalent to `approve`, and can be used to

   * e.g. set automatic allowances for certain subsystems, etc.

   *

   * Emits an {Approval} event.

   *

   * Requirements:

   *

   * - `owner` cannot be the zero address.

   * - `spender` cannot be the zero address.

   */

  function _approve(address owner, address spender, uint256 amount) internal {

    require(owner != address(0), "BEP20: approve from the zero address");

    require(spender != address(0), "BEP20: approve to the zero address");

 

    _allowances[owner][spender] = amount;

    emit Approval(owner, spender, amount);

  }

 

  /**

   * @dev Destroys `amount` tokens from `account`.`amount` is then deducted

   * from the caller's allowance.

   *

   * See {_burn} and {_approve}.

   */

  function _burnFrom(address account, uint256 amount) internal {

    _burn(account, amount);

    _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, "BEP20: burn amount exceeds allowance"));

  }

}

Vulnerability type: CWE-284|CWE-269