GHSA-VXMM-CWH2-Q762

Vulnerability from github – Published: 2023-05-22 20:35 – Updated: 2024-11-19 16:42
VLAI
Summary
Vyper's nonpayable default functions are sometimes payable
Details

Impact

in contracts with at least one regular nonpayable function, due to the callvalue check being inside of the selector section, it is possible to send funds to the default function by using less than 4 bytes of calldata, even if the default function is marked nonpayable. this applies to contracts compiled with vyper<=0.3.7.

# @version 0.3.7

# implicitly nonpayable
@external
def foo() -> uint256:
    return 1

# implicitly nonpayable
@external
def __default__():
    # could receive ether here
    pass

Patches

this was fixed by the removal of the global calldatasize check in https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520.

Workarounds

don't use nonpayable default functions

Severity
3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "vyper"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.3.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-32675"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-670"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-05-22T20:35:46Z",
    "nvd_published_at": "2023-05-19T20:15:09Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nin contracts with at least one regular nonpayable function, due to the callvalue check being inside of the selector section, it is possible to send funds to the default function by using less than 4 bytes of calldata, even if the default function is marked `nonpayable`. this applies to contracts compiled with vyper\u003c=0.3.7.\n```vyper\n# @version 0.3.7\n\n# implicitly nonpayable\n@external\ndef foo() -\u003e uint256:\n    return 1\n\n# implicitly nonpayable\n@external\ndef __default__():\n    # could receive ether here\n    pass\n```\n\n### Patches\nthis was fixed by the removal of the global calldatasize check in https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520.\n\n### Workarounds\ndon\u0027t use nonpayable default functions\n\n",
  "id": "GHSA-vxmm-cwh2-q762",
  "modified": "2024-11-19T16:42:42Z",
  "published": "2023-05-22T20:35:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-vxmm-cwh2-q762"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-32675"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/commit/02339dfda0f3caabad142060d511d10bfe93c520."
    },
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/commit/903727006c1e5ebef99fa9fd5d51d62bd33d72a9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-80.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vyperlang/vyper"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Vyper\u0027s nonpayable default functions are sometimes payable"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.