{"id":"GHSA-3whq-64q2-qfj6","summary":"vyper performs double eval of raw_args in create_from_blueprint","details":"### Summary\nUsing the `create_from_blueprint` builtin can result in a double eval vulnerability when `raw_args=True` and the `args` argument has side-effects. \n\nA contract search was performed and no vulnerable contracts were found in production. In particular, the `raw_args` variant of `create_from_blueprint` was not found to be used in production.\n\n### Details\nIt can be seen that the `_build_create_IR` function of the `create_from_blueprint` builtin doesn't cache the mentioned `args` argument to the stack: https://github.com/vyperlang/vyper/blob/cedf7087e68e67c7bfbd47ae95dcb16b81ad2e02/vyper/builtins/functions.py#L1847\n\nAs such, it can be evaluated multiple times (instead of retrieving the value from the stack).\n\n### PoC\nThe vulnerability is demonstrated in the following `boa` test:\n``` vyper\nsrc1 = \"\"\"\nc: uint256\n\"\"\"\ndeployer = \"\"\"\ncreated_address: public(address)\ndeployed: public(uint256)\n\n@external\ndef get() -\u003e Bytes[32]:\n    self.deployed += 1\n    return b''\n\n@external\ndef create_(target: address):\n    self.created_address = create_from_blueprint(target, raw_call(self, method_id(\"get()\"), max_outsize=32), raw_args=True, code_offset=3)\n\"\"\"\n\nFactory = b.loads_partial(src1)\nc = Factory.deploy_as_blueprint()\n\nc2 = b.loads(deployer, b'')\nc2.create_(c)\nc2.deployed()\n```\nThe output of `c2.deployed()` is `2` although `create_` was called only once and the value was initialized to `0`.\n\n### Patches\nPatched in https://github.com/vyperlang/vyper/pull/3976.\n\n### Impact\nNo vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is `low`.\n","aliases":["CVE-2024-32647","PYSEC-2024-208"],"modified":"2026-06-10T17:14:10.998837237Z","published":"2024-04-25T19:50:50Z","database_specific":{"cwe_ids":["CWE-95"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2024-04-25T19:50:50Z","nvd_published_at":"2024-04-25T18:15:08Z"},"references":[{"type":"WEB","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-3whq-64q2-qfj6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-32647"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2024-208.yaml"},{"type":"PACKAGE","url":"https://github.com/vyperlang/vyper"},{"type":"WEB","url":"https://github.com/vyperlang/vyper/blob/cedf7087e68e67c7bfbd47ae95dcb16b81ad2e02/vyper/builtins/functions.py#L1847"}],"affected":[{"package":{"name":"vyper","ecosystem":"PyPI","purl":"pkg:pypi/vyper"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.0"}]}],"versions":["0.1.0b1","0.1.0b10","0.1.0b11","0.1.0b12","0.1.0b13","0.1.0b14","0.1.0b15","0.1.0b16","0.1.0b17","0.1.0b2","0.1.0b3","0.1.0b4","0.1.0b5","0.1.0b6","0.1.0b7","0.1.0b8","0.1.0b9","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.14","0.2.15","0.2.16","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.10","0.3.10rc1","0.3.10rc2","0.3.10rc3","0.3.10rc4","0.3.10rc5","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0b1","0.4.0b2","0.4.0b3","0.4.0b4","0.4.0b5","0.4.0b6","0.4.0rc1","0.4.0rc2","0.4.0rc3","0.4.0rc4","0.4.0rc5","0.4.0rc6"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/04/GHSA-3whq-64q2-qfj6/GHSA-3whq-64q2-qfj6.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"}]}