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AAVE V2

96%

Previous versions

Process Quality Review (0.7)

AAVE V2

Final score:96%
Date:19 Jul 2021
Audit Process:version 0.7
Author:Nic of DeFiSafety
PQR Score:96%

PASS

Protocol Website:https://aave.com

Scoring Appendix

The final review score is indicated as a percentage. The percentage is calculated as Achieved Points due to MAX Possible Points. For each element the answer can be either Yes/No or a percentage. For a detailed breakdown of the individual weights of each question, please consult this document.

The blockchain used by this protocol
Ethereum
#QuestionAnswer
100%
1.100%
2.100%
3.Yes
4.100%
5.Yes
93%
6.Yes
7.Yes
8.100%
9.41%
10.100%
100%
11.100%
12.97%
13.Yes
14.100%
15.100%
16.100%
95%
17.100%
18.60%
89%
19.100%
20.90%
21.90%
22.80%
Total:96%

Very simply, the audit looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here is my smart contract on the blockchain
  • You can see it matches a software repository used to develop the code
  • Here is the documentation that explains what my smart contract does
  • Here are the tests I ran to verify my smart contract
  • Here are the audit(s) performed to review my code by third party experts

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2021. Permission is given to copy in whole, retaining this copyright label.

Code And Team

100%

This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here.

1. Are the executing code addresses readily available? (%)

Answer: 100%

They are available at website https://docs.aave.com/developers/deployed-contracts/deployed-contracts, as indicated in the Appendix.

Percentage Score Guidance:
100%
Clearly labelled and on website, docs or repo, quick to find
70%
Clearly labelled and on website, docs or repo but takes a bit of looking
40%
Addresses in mainnet.json, in discord or sub graph, etc
20%
Address found but labeling not clear or easy to find
0%
Executing addresses could not be found

2. Is the code actively being used? (%)

Answer: 100%

Activity is 800 transactions a day on contract InitializableImmutableAdminUpgradeabilityProxy.sol, as indicated in the Appendix.

Percentage Score Guidance:
100%
More than 10 transactions a day
70%
More than 10 transactions a week
40%
More than 10 transactions a month
10%
Less than 10 transactions a month
0%
No activity

3. Is there a public software repository? (Y/N)

Answer: Yes

Is there a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction, it gets a "Yes". For teams with private repositories, this answer is "No"

Score Guidance:
Yes
There is a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction.
No
For teams with private repositories.

4. Is there a development history visible? (%)

Answer: 100%

With 1630 commits and 40 branches in their protocol-v2, this is a robust software repository.

This metric checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Percentage Score Guidance:
100%
Any one of 100+ commits, 10+branches
70%
Any one of 70+ commits, 7+branches
50%
Any one of 50+ commits, 5+branches
30%
Any one of 30+ commits, 3+branches
0%
Less than 2 branches or less than 30 commits

5. Is the team public (not anonymous)? (Y/N)

Answer: Yes

For a "Yes" in this question, the real names of some team members must be public on the website or other documentation (LinkedIn, etc). If the team is anonymous, then this question is a "No".

Documentation

93%

This section looks at the software documentation. The document explaining these questions is here.

6. Is there a whitepaper? (Y/N)

Answer: Yes

7. Are the basic software functions documented? (Y/N)

Answer: Yes

The AAVE software functions (code) are all well-documented in "The Core Protocol" section of their documentation.

8. Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 100%

All the AAVE core protocols have their software functions documented here, as well as governance functions here, and API documentation here, and additional NPM documentation here.

Percentage Score Guidance:
100%
All contracts and functions documented
80%
Only the major functions documented
79 - 1%
Estimate of the level of software documentation
0%
No software documentation

9. Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 41%

Code examples are in the Appendix. As per the SLOC, there is 41% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Percentage Score Guidance:
100%
CtC > 100 Useful comments consistently on all code
90 - 70%
CtC > 70 Useful comment on most code
60 - 20%
CtC > 20 Some useful commenting
0%
CtC < 20 No useful commenting

10. Is it possible to trace from software documentation to the implementation in code (%)

Answer: 100%

There is clear and explicit traceability between the documented software functions and their implementation within the AAVE source code. A good example of this can be seen here.

Percentage Score Guidance:
100%
Clear explicit traceability between code and documentation at a requirement level for all code
60%
Clear association between code and documents via non explicit traceability
40%
Documentation lists all the functions and describes their functions
0%
No connection between documentation and code

Testing

100%

11. Full test suite (Covers all the deployed code) (%)

Answer: 100%

Code examples are in the Appendix. As per the SLOC, there is 349% testing to code (TtC).

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Percentage Score Guidance:
100%
TtC > 120% Both unit and system test visible
80%
TtC > 80% Both unit and system test visible
40%
TtC < 80% Some tests visible
0%
No tests obvious

12. Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 97%

There is evidence of AAVE code coverage in their SigmaPrime audit report, however they do not explain skips or misses. In addition, they also have 99% codecov in their Governance repository.

Percentage Score Guidance:
100%
Documented full coverage
99 - 51%
Value of test coverage from documented results
50%
No indication of code coverage but clearly there is a reasonably complete set of tests
30%
Some tests evident but not complete
0%
No test for coverage seen

13. Scripts and instructions to run the tests? (Y/N)

Answer: Yes

Scrips/Instructions location: Instructions to run tests can be found in the README.​

14. Report of the results (%)

Answer: 100%

As well as their SigmaPrime coverage report, AAVE has their own report here, and governance codecov report here​.

Percentage Score Guidance:
100%
Detailed test report as described below
70%
GitHub code coverage report visible
0%
No test report evident

15. Formal Verification test done (%)

Answer: 100%

AAVE has had a Formal Verification test done by Certora.

16. Stress Testing environment (%)

Answer: 100%

There is evidence of AAVE Kovan test-net smart contract usage at https://docs.aave.com/developers/deployed-contracts/deployed-contracts.

Security

95%

This section looks at the 3rd party software audits done. It is explained in this document.

17. Did 3rd Party audits take place? (%)

Answer: 100%

Multiple high-quality AAVE audit reports were published before and after V1 and V2 deployment. The results were also implemented. These reports can be found at https://docs.aave.com/risk/audits/smartcontract-audits.

Percentage Score Guidance:
100%
Multiple Audits performed before deployment and results public and implemented or not required
90%
Single audit performed before deployment and results public and implemented or not required
70%
Audit(s) performed after deployment and no changes required. Audit report is public
50%
Audit(s) performed after deployment and changes needed but not implemented
20%
No audit performed
0%
Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address not found, (where question 1 is 0%)
Deduct 25% if code is in a private repo and no note from auditors that audit is applicable to deployed code.

18. Is the bug bounty acceptable high? (%)

Answer: 60%

AAVE's Bug Bounty program offers up to 250k in rewards.

Percentage Score Guidance:
100%
Bounty is 10% TVL or at least $1M AND active program (see below)
90%
Bounty is 5% TVL or at least 500k AND active program
80%
Bounty is 5% TVL or at least 500k
70%
Bounty is 100k or over AND active program
60%
Bounty is 100k or over
50%
Bounty is 50k or over AND active program
40%
Bounty is 50k or over
20%
Bug bounty program bounty is less than 50k
0%
No bug bounty program offered
An active program means that a third party (such as Immunefi) is actively driving hackers to the site. An inactive program would be static mentions on the docs.

Access Controls

89%

This section covers the documentation of special access controls for a DeFi protocol. The admin access controls are the contracts that allow updating contracts or coefficients in the protocol. Since these contracts can allow the protocol admins to "change the rules", complete disclosure of capabilities is vital for user's transparency. It is explained in this document.

19. Can a user clearly and quickly find the status of the access controls (%)

Answer: 100%

AAVE admin access control information can easily be found at https://docs.aave.com/developers/protocol-governance/governance.

Percentage Score Guidance:
100%
Clearly labelled and on website, docs or repo, quick to find
70%
Clearly labelled and on website, docs or repo but takes a bit of looking
40%
Access control docs in multiple places and not well labelled
20%
Access control docs in multiple places and not labelled
0%
Admin Control information could not be found

20. Is the information clear and complete (%)

Answer: 90%

a) Some protocols are clearly labelled as immutable (i.e LendingPoolAddressesProvider), and others are clearly labelled as upgradeable.

Percentage Score Guidance:
All the contracts are immutable -- 100% OR
a) All contracts are clearly labelled as upgradeable (or not) -- 30% AND
b) The type of ownership is clearly indicated (OnlyOwner / MultiSig / Defined Roles) -- 30% AND
c) The capabilities for change in the contracts are described -- 30%

21. Is the information in non-technical terms that pertain to the investments (%)

Answer: 90%

They have a technical and non-technical set of documentation.

Percentage Score Guidance:
100%
All the contracts are immutable
90%
Description relates to investments safety and updates in clear, complete non-software language
30%
Description all in software specific language
0%
No admin control information could be found

22. Is there Pause Control documentation including records of tests (%)

Answer: 80%

The AAVE Pause Control function is called Pause Guardian and is documented in the governance subgraph and tests from May 2021 can be found at https://github.com/aave/governance-v2/blob/f16655ae3d91d6043c5e345f59c0111d8207771b/test/governance-admin.spec.ts.

Percentage Score Guidance:
100%
All the contracts are immutable or no pause control needed and this is explained OR Pause control(s) are clearly documented and there is records of at least one test within 3 months
80%
Pause control(s) explained clearly but no evidence of regular tests
40%
Pause controls mentioned with no detail on capability or tests
0%
Pause control not documented or explained

Appendices

 The author of this review is Rex of DeFi Safety.

Email: rex@defisafety.com
Twitter: @defisafety

I started with Ethereum just before the DAO and that was a wonderful education.  It showed the importance of code quality. The second Parity hack also showed the importance of good process.  Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.
I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development. DeFiSafety is my full time gig and we are working on funding vehicles for a permanent staff.

1contract LendingPool is VersionedInitializable, ILendingPool, LendingPoolStorage {
2  using SafeMath for uint256;
3  using WadRayMath for uint256;
4  using PercentageMath for uint256;
5  using SafeERC20 for IERC20;
67  uint256 public constant LENDINGPOOL_REVISION = 0x2;
89  modifier whenNotPaused() {
10    _whenNotPaused();
11    _;
12  }
1314  modifier onlyLendingPoolConfigurator() {
15    _onlyLendingPoolConfigurator();
16    _;
17  }
1819  function _whenNotPaused() internal view {
20    require(!_paused, Errors.LP_IS_PAUSED);
21  }
2223  function _onlyLendingPoolConfigurator() internal view {
24    require(
25      _addressesProvider.getLendingPoolConfigurator() == msg.sender,
26      Errors.LP_CALLER_NOT_LENDING_POOL_CONFIGURATOR
27    );
28  }
2930  function getRevision() internal pure override returns (uint256) {
31    return LENDINGPOOL_REVISION;
32  }
3334  /**
35   * @dev Function is invoked by the proxy contract when the LendingPool contract is added to the
36   * LendingPoolAddressesProvider of the market.
37   * - Caching the address of the LendingPoolAddressesProvider in order to reduce gas consumption
38   *   on subsequent operations
39   * @param provider The address of the LendingPoolAddressesProvider
40   **/
41  function initialize(ILendingPoolAddressesProvider provider) public initializer {
42    _addressesProvider = provider;
43    _maxStableRateBorrowSizePercent = 2500;
44    _flashLoanPremiumTotal = 9;
45    _maxNumberOfReserves = 128;
46  }
4748  /**
49   * @dev Deposits an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
50   * - E.g. User deposits 100 USDC and gets in return 100 aUSDC
51   * @param asset The address of the underlying asset to deposit
52   * @param amount The amount to be deposited
53   * @param onBehalfOf The address that will receive the aTokens, same as msg.sender if the user
54   *   wants to receive them on his own wallet, or a different address if the beneficiary of aTokens
55   *   is a different wallet
56   * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
57   *   0 if the action is executed directly by the user, without any middle-man
58   **/
59  function deposit(
60    address asset,
61    uint256 amount,
62    address onBehalfOf,
63    uint16 referralCode
64  ) external override whenNotPaused {
65    DataTypes.ReserveData storage reserve = _reserves[asset];
6667    ValidationLogic.validateDeposit(reserve, amount);
6869    address aToken = reserve.aTokenAddress;
7071    reserve.updateState();
72    reserve.updateInterestRates(asset, aToken, amount, 0);
7374    IERC20(asset).safeTransferFrom(msg.sender, aToken, amount);
7576    bool isFirstDeposit = IAToken(aToken).mint(onBehalfOf, amount, reserve.liquidityIndex);
7778    if (isFirstDeposit) {
79      _usersConfig[onBehalfOf].setUsingAsCollateral(reserve.id, true);
80      emit ReserveUsedAsCollateralEnabled(asset, onBehalfOf);
81    }
8283    emit Deposit(asset, msg.sender, onBehalfOf, amount, referralCode);
84  }
8586  /**
87   * @dev Withdraws an `amount` of underlying asset from the reserve, burning the equivalent aTokens owned
88   * E.g. User has 100 aUSDC, calls withdraw() and receives 100 USDC, burning the 100 aUSDC
89   * @param asset The address of the underlying asset to withdraw
90   * @param amount The underlying amount to be withdrawn
91   *   - Send the value type(uint256).max in order to withdraw the whole aToken balance
92   * @param to Address that will receive the underlying, same as msg.sender if the user
93   *   wants to receive it on his own wallet, or a different address if the beneficiary is a
94   *   different wallet
95   * @return The final amount withdrawn
96   **/
97  function withdraw(
98    address asset,
99    uint256 amount,
100    address to
101  ) external override whenNotPaused returns (uint256) {
102    DataTypes.ReserveData storage reserve = _reserves[asset];
103104    address aToken = reserve.aTokenAddress;
105106    uint256 userBalance = IAToken(aToken).balanceOf(msg.sender);
107108    uint256 amountToWithdraw = amount;
109110    if (amount == type(uint256).max) {
111      amountToWithdraw = userBalance;
112    }
113114    ValidationLogic.validateWithdraw(
115      asset,
116      amountToWithdraw,
117      userBalance,
118      _reserves,
119      _usersConfig[msg.sender],
120      _reservesList,
121      _reservesCount,
122      _addressesProvider.getPriceOracle()
123    );
124125    reserve.updateState();
126127    reserve.updateInterestRates(asset, aToken, 0, amountToWithdraw);
128129    if (amountToWithdraw == userBalance) {
130      _usersConfig[msg.sender].setUsingAsCollateral(reserve.id, false);
131      emit ReserveUsedAsCollateralDisabled(asset, msg.sender);
132    }
133134    IAToken(aToken).burn(msg.sender, to, amountToWithdraw, reserve.liquidityIndex);
135136    emit Withdraw(asset, msg.sender, to, amountToWithdraw);
137138    return amountToWithdraw;
139  }
140141  /*
142   * @dev Allows users to borrow a specific `amount` of the reserve underlying asset, provided that the borrower
143   * already deposited enough collateral, or he was given enough allowance by a credit delegator on the
144   * corresponding debt token (StableDebtToken or VariableDebtToken)
145   * - E.g. User borrows 100 USDC passing as `onBehalfOf` his own address, receiving the 100 USDC in his wallet
146   *   and 100 stable/variable debt tokens, depending on the `interestRateMode`
147   * @param asset The address of the underlying asset to borrow
148   * @param amount The amount to be borrowed
149   * @param interestRateMode The interest rate mode at which the user wants to borrow: 1 for Stable, 2 for Variable
150   * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
151   *   0 if the action is executed directly by the user, without any middle-man
152   * @param onBehalfOf Address of the user who will receive the debt. Should be the address of the borrower itself
153   * calling the function if he wants to borrow against his own collateral, or the address of the credit delegator
154   * if he has been given credit delegation allowance
155   */
156  function borrow(
157    address asset,
158    uint256 amount,
159    uint256 interestRateMode,
160    uint16 referralCode,
161    address onBehalfOf
162  ) external override whenNotPaused {
163    DataTypes.ReserveData storage reserve = _reserves[asset];
164165    _executeBorrow(
166      ExecuteBorrowParams(
167        asset,
168        msg.sender,
169        onBehalfOf,
170        amount,
171        interestRateMode,
172        reserve.aTokenAddress,
173        referralCode,
174        true

Solidity Contracts

Language
Files
Lines
Blanks
Comments
Code
Complexity
Solidity
24
5885
766
1501
3618
281

Comments to Code: 1501 / 3618 =  41 %

JavaScript Tests

Language
Files
Lines
Blanks
Comments
Code
Complexity
TypeScript
34
12208
2073
718
9417
391
JSON
10
3221
6
0
3215
0
Total
44
15429
2079
718
12632
391

Tests to Code: 12632 / 3618 = 349 %