{"componentChunkName":"component---node-modules-rocketseat-gatsby-theme-docs-core-src-templates-docs-query-js","path":"/manual-review/MetaRouterV2-MRV","result":{"data":{"mdx":{"id":"f521e44a-7523-5738-90ef-a740ac1cd0d8","excerpt":"MRV-01M: Inexistent Validation of Calldata Slots Type Severity Location Input Sanitization MetaRouterV2.sol:L58 ,  L83 Description: The low level  assembly…","fields":{"slug":"/manual-review/MetaRouterV2-MRV/"},"frontmatter":{"title":"MetaRouterV2 Manual Review Findings","description":"Contains all the findings that relate to manual review on the contract codebase","image":null,"disableTableOfContents":null},"body":"var _excluded = [\"components\"];\n\nfunction _extends() { _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; return _extends.apply(this, arguments); }\n\nfunction _objectWithoutProperties(source, excluded) { if (source == null) return {}; var target = _objectWithoutPropertiesLoose(source, excluded); var key, i; if (Object.getOwnPropertySymbols) { var sourceSymbolKeys = Object.getOwnPropertySymbols(source); for (i = 0; i < sourceSymbolKeys.length; i++) { key = sourceSymbolKeys[i]; if (excluded.indexOf(key) >= 0) continue; if (!Object.prototype.propertyIsEnumerable.call(source, key)) continue; target[key] = source[key]; } } return target; }\n\nfunction _objectWithoutPropertiesLoose(source, excluded) { if (source == null) return {}; var target = {}; var sourceKeys = Object.keys(source); var key, i; for (i = 0; i < sourceKeys.length; i++) { key = sourceKeys[i]; if (excluded.indexOf(key) >= 0) continue; target[key] = source[key]; } return target; }\n\n/* @jsxRuntime classic */\n\n/* @jsx mdx */\nvar _frontmatter = {\n  \"title\": \"MetaRouterV2 Manual Review Findings\",\n  \"description\": \"Contains all the findings that relate to manual review on the contract codebase\"\n};\nvar layoutProps = {\n  _frontmatter: _frontmatter\n};\nvar MDXLayout = \"wrapper\";\nreturn function MDXContent(_ref) {\n  var components = _ref.components,\n      props = _objectWithoutProperties(_ref, _excluded);\n\n  return mdx(MDXLayout, _extends({}, layoutProps, props, {\n    components: components,\n    mdxType: \"MDXLayout\"\n  }), mdx(\"h2\", {\n    \"id\": \"span-idmrv-01mmrv-01m-inexistent-validation-of-calldata-slotsspan\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h2\",\n    \"href\": \"#span-idmrv-01mmrv-01m-inexistent-validation-of-calldata-slotsspan\",\n    \"aria-label\": \"span idmrv 01mmrv 01m inexistent validation of calldata slotsspan permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), mdx(\"span\", {\n    id: \"MRV-01M\"\n  }, \"MRV-01M: Inexistent Validation of Calldata Slots\")), mdx(\"table\", null, mdx(\"thead\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"thead\"\n  }, mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Type\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Severity\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Location\"))), mdx(\"tbody\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"tbody\"\n  }, mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"/symbiosis-finance-router-bridge/appendix/finding-types#input-sanitization\"\n  }, \"Input Sanitization\")), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"img\", {\n    parentName: \"td\",\n    \"className\": \"o-severity o-medium\",\n    \"src\": \"https://omniscia.io/report-assets/medium.png\"\n  })), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L58\"\n  }, \"MetaRouterV2.sol:L58\"), \", \", mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L83\"\n  }, \"L83\"))))), mdx(\"h3\", {\n    \"id\": \"description\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#description\",\n    \"aria-label\": \"description permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Description:\"), mdx(\"p\", null, \"The low level \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"assembly\"), \" writes to the two call datas are meant to fill in the value of a particular argument for the external call, however, no validation is performed on the calldata that can lead to out-of-bounds writes in the blocks as well as generally unexpected behaviour.\"), mdx(\"h3\", {\n    \"id\": \"example\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#example\",\n    \"aria-label\": \"example permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Example:\"), mdx(\"pre\", null, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-sol\",\n    \"metastring\": \"title=contracts/metarouter/MetaRouterV2.sol highlight={6,31} lineNumbers=true lineOffset=52\",\n    \"title\": \"contracts/metarouter/MetaRouterV2.sol\",\n    \"highlight\": \"{6,31}\",\n    \"lineNumbers\": \"true\",\n    \"lineOffset\": \"52\"\n  }, \"uint256 finalSwapAmountIn = secondSwapAmountIn;\\nif (_metarouteTransaction.secondSwapCalldata.length != 0) {\\n    bytes memory secondSwapCalldata = _metarouteTransaction.secondSwapCalldata;\\n\\n    assembly {\\n        mstore(add(secondSwapCalldata, 100), secondSwapAmountIn)\\n    }\\n\\n    IERC20(_metarouteTransaction.approvedTokens[approvedTokensLength - 2]).approve(\\n        _metarouteTransaction.secondDexRouter,\\n        secondSwapAmountIn\\n    );\\n\\n    (bool secondSwapSuccess,) = _metarouteTransaction.secondDexRouter.call(\\n        secondSwapCalldata\\n    );\\n    require(secondSwapSuccess, \\\"MetaRouterV2: second swap failed\\\");\\n\\n    finalSwapAmountIn = IERC20(\\n        _metarouteTransaction.approvedTokens[approvedTokensLength - 1]\\n    ).balanceOf(address(this));\\n}\\n\\nIERC20(_metarouteTransaction.approvedTokens[approvedTokensLength - 1]).approve(\\n    _metarouteTransaction.relayRecipient,\\n    finalSwapAmountIn\\n);\\n\\nbytes memory otherSideCalldata = _metarouteTransaction.otherSideCalldata;\\nassembly {\\n    mstore(add(otherSideCalldata, 100), finalSwapAmountIn)\\n}\\n\")), mdx(\"h3\", {\n    \"id\": \"recommendation\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#recommendation\",\n    \"aria-label\": \"recommendation permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Recommendation:\"), mdx(\"p\", null, \"We advise the calldata arguments to be validated by at least mandating they are of a particular \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"length\"), \".\"), mdx(\"h3\", {\n    \"id\": \"alleviation\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#alleviation\",\n    \"aria-label\": \"alleviation permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Alleviation:\"), mdx(\"p\", null, \"After consideration of our exhibit & with the help of an external party, the Symbiosis Finance team identified a potential attack vector based on allowances set to the contract that arbitrary calls could exploit. The Symbiosis Finance team introduced the concept of a gateway contract that is meant to instead be set an allowance for by external users preventing the arbitrary calls performed by the \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"MetaRouterV2\"), \" contract to be able to tap into allowances set for it. Additionally, the two arbitrary calls performed now cannot have the gateway contract as a target thereby completely nullifying any attack vector that would affect user funds and rendering the contract secure. After additional discussion with the Symbiosis Finance team, we concluded that malicious data stacks for the linked \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"assembly\"), \" blocks would only affect the caller and would not pose a threat to other users or the network's state. As a result, this exhibit is considered dealt with.\"), mdx(ViewDiffButton, {\n    repoUrl: \"https://github.com/symbiosis-finance/contracts-audit-with-tests\",\n    mainHash: \"707f038827af3c900419d36a58c1ad5def057e4c\",\n    fixHash: \"dd00ff393914aaaa3aa3b2d0a65d5cf3ec4c42e2\",\n    mdxType: \"ViewDiffButton\"\n  }), mdx(\"h2\", {\n    \"id\": \"span-idmrv-02mmrv-02m-arbitrary-approvalsspan\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h2\",\n    \"href\": \"#span-idmrv-02mmrv-02m-arbitrary-approvalsspan\",\n    \"aria-label\": \"span idmrv 02mmrv 02m arbitrary approvalsspan permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), mdx(\"span\", {\n    id: \"MRV-02M\"\n  }, \"MRV-02M: Arbitrary Approvals\")), mdx(\"table\", null, mdx(\"thead\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"thead\"\n  }, mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Type\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Severity\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Location\"))), mdx(\"tbody\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"tbody\"\n  }, mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"/symbiosis-finance-router-bridge/appendix/finding-types#logical-fault\"\n  }, \"Logical Fault\")), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"img\", {\n    parentName: \"td\",\n    \"className\": \"o-severity o-minor\",\n    \"src\": \"https://omniscia.io/report-assets/minor.png\"\n  })), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L36-L39\"\n  }, \"MetaRouterV2.sol:L36-L39\"), \", \", mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L61-L64\"\n  }, \"L61-L64\"), \", \", mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L76-L79\"\n  }, \"L76-L79\"))))), mdx(\"h3\", {\n    \"id\": \"description-1\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#description-1\",\n    \"aria-label\": \"description 1 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Description:\"), mdx(\"p\", null, \"The contract performs arbitrary \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"approve\"), \" invocations which allow crafted payloads to extract any funds at rest within the contract.\"), mdx(\"h3\", {\n    \"id\": \"example-1\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#example-1\",\n    \"aria-label\": \"example 1 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Example:\"), mdx(\"pre\", null, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-sol\",\n    \"metastring\": \"title=contracts/metarouter/MetaRouterV2.sol highlight={19,20,21,22,44,45,46,47,59,60,61,62} lineNumbers=true lineOffset=17\",\n    \"title\": \"contracts/metarouter/MetaRouterV2.sol\",\n    \"highlight\": \"{19,20,21,22,44,45,46,47,59,60,61,62}\",\n    \"lineNumbers\": \"true\",\n    \"lineOffset\": \"17\"\n  }, \"function metaRouteV2(\\n    MetaRouteStructs.MetaRouteTransactionV2 memory _metarouteTransaction\\n) external payable {\\n    uint256 firstSwapValue;\\n    uint256 approvedTokensLength = _metarouteTransaction.approvedTokens.length;\\n\\n    if (!_metarouteTransaction.nativeIn) {\\n        TransferHelper.safeTransferFrom(\\n            _metarouteTransaction.approvedTokens[0],\\n            _msgSender(),\\n            address(this),\\n            _metarouteTransaction.amount\\n        );\\n    }\\n\\n    uint256 secondSwapAmountIn = _metarouteTransaction.amount;\\n    if (_metarouteTransaction.firstSwapCalldata.length != 0) {\\n        if (!_metarouteTransaction.nativeIn) {\\n            IERC20(_metarouteTransaction.approvedTokens[0]).approve(\\n                _metarouteTransaction.firstDexRouter,\\n                _metarouteTransaction.amount\\n            );\\n        }\\n\\n        (bool firstSwapSuccess,) = _metarouteTransaction\\n        .firstDexRouter\\n        .call{value : msg.value}(_metarouteTransaction.firstSwapCalldata);\\n\\n        require(firstSwapSuccess, \\\"MetaRouterV2: first swap failed\\\");\\n\\n        secondSwapAmountIn = IERC20(\\n            _metarouteTransaction.approvedTokens[1]\\n        ).balanceOf(address(this));\\n    }\\n\\n    uint256 finalSwapAmountIn = secondSwapAmountIn;\\n    if (_metarouteTransaction.secondSwapCalldata.length != 0) {\\n        bytes memory secondSwapCalldata = _metarouteTransaction.secondSwapCalldata;\\n\\n        assembly {\\n            mstore(add(secondSwapCalldata, 100), secondSwapAmountIn)\\n        }\\n\\n        IERC20(_metarouteTransaction.approvedTokens[approvedTokensLength - 2]).approve(\\n            _metarouteTransaction.secondDexRouter,\\n            secondSwapAmountIn\\n        );\\n\\n        (bool secondSwapSuccess,) = _metarouteTransaction.secondDexRouter.call(\\n            secondSwapCalldata\\n        );\\n        require(secondSwapSuccess, \\\"MetaRouterV2: second swap failed\\\");\\n\\n        finalSwapAmountIn = IERC20(\\n            _metarouteTransaction.approvedTokens[approvedTokensLength - 1]\\n        ).balanceOf(address(this));\\n    }\\n\\n    IERC20(_metarouteTransaction.approvedTokens[approvedTokensLength - 1]).approve(\\n        _metarouteTransaction.relayRecipient,\\n        finalSwapAmountIn\\n    );\\n\\n    bytes memory otherSideCalldata = _metarouteTransaction.otherSideCalldata;\\n    assembly {\\n        mstore(add(otherSideCalldata, 100), finalSwapAmountIn)\\n    }\\n\\n    (bool otherSideCallSuccess,) = _metarouteTransaction.relayRecipient\\n                                        .call(otherSideCalldata);\\n    require(otherSideCallSuccess, \\\"MetaRouterV2: other side call failed\\\");\\n}\\n\")), mdx(\"h3\", {\n    \"id\": \"recommendation-1\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#recommendation-1\",\n    \"aria-label\": \"recommendation 1 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Recommendation:\"), mdx(\"p\", null, \"While funds are not expected to remain at rest, it is still advisable to perform approvals only to authorized exchanges and to validate that a swap was indeed made before performing the final transaction. In general, the router should identify the amounts it received via the return arguments of the swaps rather than rely on dynamic \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"balanceOf\"), \" invocations.\"), mdx(\"h3\", {\n    \"id\": \"alleviation-1\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#alleviation-1\",\n    \"aria-label\": \"alleviation 1 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Alleviation:\"), mdx(\"p\", null, \"The Symbiosis Finance team stated that given the context of the contract any allowance will not pose a threat to other users or the network and as such they opt to not remediate it.\"), mdx(\"h2\", {\n    \"id\": \"span-idmrv-03mmrv-03m-ill-advised-allowance-patternspan\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h2\",\n    \"href\": \"#span-idmrv-03mmrv-03m-ill-advised-allowance-patternspan\",\n    \"aria-label\": \"span idmrv 03mmrv 03m ill advised allowance patternspan permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), mdx(\"span\", {\n    id: \"MRV-03M\"\n  }, \"MRV-03M: Ill-Advised Allowance Pattern\")), mdx(\"table\", null, mdx(\"thead\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"thead\"\n  }, mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Type\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Severity\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Location\"))), mdx(\"tbody\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"tbody\"\n  }, mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"/symbiosis-finance-router-bridge/appendix/finding-types#standard-conformity\"\n  }, \"Standard Conformity\")), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"img\", {\n    parentName: \"td\",\n    \"className\": \"o-severity o-minor\",\n    \"src\": \"https://omniscia.io/report-assets/minor.png\"\n  })), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L145-L148\"\n  }, \"MetaRouterV2.sol:L145-L148\"))))), mdx(\"h3\", {\n    \"id\": \"description-2\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#description-2\",\n    \"aria-label\": \"description 2 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Description:\"), mdx(\"p\", null, \"The linked code performs an \\\"infinity\\\" allowance to the router it is meant to interact with, a programming paradigm that is advised against.\"), mdx(\"h3\", {\n    \"id\": \"example-2\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#example-2\",\n    \"aria-label\": \"example 2 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Example:\"), mdx(\"pre\", null, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-sol\",\n    \"metastring\": \"title=contracts/metarouter/MetaRouterV2.sol highlight={11} lineNumbers=true lineOffset=136\",\n    \"title\": \"contracts/metarouter/MetaRouterV2.sol\",\n    \"highlight\": \"{11}\",\n    \"lineNumbers\": \"true\",\n    \"lineOffset\": \"136\"\n  }, \"function _swap(\\n    address _token,\\n    uint256 _amount,\\n    address _router,\\n    bytes memory _swapCalldata,\\n    uint256 _offset\\n) internal returns (bool success) {\\n    if (IERC20(_token).allowance(address(this), _router) < _amount) {\\n        IERC20(_token).approve(\\n            _router,\\n            type(uint256).max\\n        );\\n    }\\n\\n    assembly {\\n        mstore(add(_swapCalldata, _offset), _amount)\\n    }\\n\\n    (success, ) = _router.call(_swapCalldata);\\n}\\n\")), mdx(\"h3\", {\n    \"id\": \"recommendation-2\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#recommendation-2\",\n    \"aria-label\": \"recommendation 2 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Recommendation:\"), mdx(\"p\", null, \"We advise the allowance to be set to exactly the value necessary to avoid potential complications due to unspent \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"allowance\"), \".\"), mdx(\"h3\", {\n    \"id\": \"alleviation-2\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#alleviation-2\",\n    \"aria-label\": \"alleviation 2 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Alleviation:\"), mdx(\"p\", null, \"The Symbiosis Finance team stated that given the context of the contract any allowance will not pose a threat to other users or the network and as such they opt to not remediate it.\"), mdx(\"h2\", {\n    \"id\": \"span-idmrv-04mmrv-04m-improper-receive-functionspan\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h2\",\n    \"href\": \"#span-idmrv-04mmrv-04m-improper-receive-functionspan\",\n    \"aria-label\": \"span idmrv 04mmrv 04m improper receive functionspan permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), mdx(\"span\", {\n    id: \"MRV-04M\"\n  }, \"MRV-04M: Improper \", mdx(\"inlineCode\", {\n    parentName: \"h2\"\n  }, \"receive\"), \" Function\")), mdx(\"table\", null, mdx(\"thead\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"thead\"\n  }, mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Type\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Severity\"), mdx(\"th\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, \"Location\"))), mdx(\"tbody\", {\n    parentName: \"table\"\n  }, mdx(\"tr\", {\n    parentName: \"tbody\"\n  }, mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"/symbiosis-finance-router-bridge/appendix/finding-types#logical-fault\"\n  }, \"Logical Fault\")), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"img\", {\n    parentName: \"td\",\n    \"className\": \"o-severity o-minor\",\n    \"src\": \"https://omniscia.io/report-assets/minor.png\"\n  })), mdx(\"td\", {\n    parentName: \"tr\",\n    \"align\": null\n  }, mdx(\"a\", {\n    parentName: \"td\",\n    \"href\": \"https://github.com/symbiosis-finance/contracts-audit-with-tests/blob/707f038827af3c900419d36a58c1ad5def057e4c/contracts/metarouter/MetaRouterV2.sol#L15\"\n  }, \"MetaRouterV2.sol:L15\"))))), mdx(\"h3\", {\n    \"id\": \"description-3\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#description-3\",\n    \"aria-label\": \"description 3 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Description:\"), mdx(\"p\", null, \"The \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"MetaRouterV2\"), \" contract is able to receive native assets, however, no function exists in the contract that utilizes funds received as an argument.\"), mdx(\"h3\", {\n    \"id\": \"example-3\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#example-3\",\n    \"aria-label\": \"example 3 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Example:\"), mdx(\"pre\", null, mdx(\"code\", {\n    parentName: \"pre\",\n    \"className\": \"language-sol\",\n    \"metastring\": \"title=contracts/metarouter/MetaRouterV2.sol highlight={1} lineNumbers=true lineOffset=14\",\n    \"title\": \"contracts/metarouter/MetaRouterV2.sol\",\n    \"highlight\": \"{1}\",\n    \"lineNumbers\": \"true\",\n    \"lineOffset\": \"14\"\n  }, \"receive() external payable {}\\n\")), mdx(\"h3\", {\n    \"id\": \"recommendation-3\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#recommendation-3\",\n    \"aria-label\": \"recommendation 3 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Recommendation:\"), mdx(\"p\", null, \"Presumably, this function was introduced to allow native outputs in the swaps the contract performs, however, no outward native asset transfer is performed by the contract that utilizes converted or existing (\", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"address(this).balance\"), \") funds. As a result, we advise the function to be omitted from the contract.\"), mdx(\"h3\", {\n    \"id\": \"alleviation-3\",\n    \"style\": {\n      \"position\": \"relative\"\n    }\n  }, mdx(\"a\", {\n    parentName: \"h3\",\n    \"href\": \"#alleviation-3\",\n    \"aria-label\": \"alleviation 3 permalink\",\n    \"className\": \"anchor before\"\n  }, mdx(\"svg\", {\n    parentName: \"a\",\n    \"aria-hidden\": \"true\",\n    \"focusable\": \"false\",\n    \"height\": \"16\",\n    \"version\": \"1.1\",\n    \"viewBox\": \"0 0 16 16\",\n    \"width\": \"16\"\n  }, mdx(\"path\", {\n    parentName: \"svg\",\n    \"fillRule\": \"evenodd\",\n    \"d\": \"M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z\"\n  }))), \"Alleviation:\"), mdx(\"p\", null, \"The \", mdx(\"inlineCode\", {\n    parentName: \"p\"\n  }, \"receive\"), \" function has been omitted from the codebase as per our recommendation.\"), mdx(ViewDiffButton, {\n    repoUrl: \"https://github.com/symbiosis-finance/contracts-audit-with-tests\",\n    mainHash: \"707f038827af3c900419d36a58c1ad5def057e4c\",\n    fixHash: \"796b5eef153db2321446b60651de9f2d22d233c0\",\n    mdxType: \"ViewDiffButton\"\n  }));\n}\n;\nMDXContent.isMDXComponent = true;","headings":[{"depth":2,"value":"<span id=\"MRV-01M\">MRV-01M: Inexistent Validation of Calldata Slots</span>"},{"depth":3,"value":"Description:"},{"depth":3,"value":"Example:"},{"depth":3,"value":"Recommendation:"},{"depth":3,"value":"Alleviation:"},{"depth":2,"value":"<span id=\"MRV-02M\">MRV-02M: Arbitrary Approvals</span>"},{"depth":3,"value":"Description:"},{"depth":3,"value":"Example:"},{"depth":3,"value":"Recommendation:"},{"depth":3,"value":"Alleviation:"},{"depth":2,"value":"<span id=\"MRV-03M\">MRV-03M: Ill-Advised Allowance Pattern</span>"},{"depth":3,"value":"Description:"},{"depth":3,"value":"Example:"},{"depth":3,"value":"Recommendation:"},{"depth":3,"value":"Alleviation:"},{"depth":2,"value":"<span id=\"MRV-04M\">MRV-04M: Improper receive Function</span>"},{"depth":3,"value":"Description:"},{"depth":3,"value":"Example:"},{"depth":3,"value":"Recommendation:"},{"depth":3,"value":"Alleviation:"}]}},"pageContext":{"slug":"/manual-review/MetaRouterV2-MRV/","prev":{"label":"BridgeV2.sol (BV2-M)","link":"/manual-review/BridgeV2-BV2"},"next":{"label":"Portal.sol (POR-M)","link":"/manual-review/Portal-POR"}}},"staticQueryHashes":["1954253342","2328931024","2501019404","973074209"]}