QA Report

[code423n4]

1. Reentrancy issue in a function
   The functions below have an external call which can allow user to reenter into the function. Although reentering the function would cause harm to the caller than good.

**Occurrences in:
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/AmmGauge.sol#L130-L134
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/AmmGauge.sol#L108-L111

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2. Missing events and emit
   Certain events and emits are necessary for core changes and admin/critical activities to allow monitoring on third party tools. The following below are missing;

**Occurrences in:
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L68
https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L74
https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/Minter.sol#L99

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3.. Missing zero address check
The following are missing checks for existence of zero address which may lead to transfers to zero address or causing some functions to no longer be accessible.

**Occurrences in:
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/AmmGauge.sol#L124
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/AmmGauge.sol#L56
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/AmmGauge.sol#L103
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/BkdLocker.sol#L70
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/FeeBurner.sol#L31
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/FeeBurner.sol#L31
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/StakerVault.sol#L111
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/StakerVault.sol#L139
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/StakerVault.sol#L359
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/Minter.sol#L126
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/Minter.sol#L144
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L65

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4. Use of Deprecated safeApprove() function
   The OpenZeppelin ERC20 SafeApprove() function has been deprecated, replace safeApprove() with safeIncreaseAllowance() or safeDecreaseAllowance() instead.

**Occurrences in:
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/RewardHandler.sol#L52
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/RewardHandler.sol#L64
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/FeeBurner.sol#L118
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/zaps/PoolMigrationZap.sol#L27

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5. Max approvals are risky
   Maximum approvals are widely considered as unsafe if the approved contract becomes compromised/malicious.

**Occurrences in:
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/RewardHandler.sol#L64
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/FeeBurner.sol#L118

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6.. Costly external calls in a loop
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/Controller.sol#L127
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/RewardHandler.sol#L44
*https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/RewardHandler.sol#L44
https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/FeeBurner.sol#L70
https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L99
https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L102

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7. Use of unsafe approve()
   https://github.com/code-423n4/2022-05-backd/blob/main/protocol/contracts/tokenomics/VestedEscrow.sol#L25

[GalloDaSballo]

Reentrancy issue in a function

Would rephrase to lack of CEI pattern, as no reEntrancy was demonstrated

Missing events and emit

Informational

3.. Missing zero address check

Valid

Use of Deprecated safeApprove() function

Technically valid but safeApprove is being used correctly throughout the codebase

Max approvals are risky

In lack of alternative, the one line comment is not useful

6.. Costly external calls in a loop

In lack of a suggested refactoring, the one line comment is not useful

Use of unsafe approve()

Agree that this needs to be changed, and believe Low Severity to be appropriate because this is happening in a constructor