GHSA-cx2q-hfxr-rj97
Vulnerability from github
Impact
_abi_decode() does not validate input when it is nested in an expression. the following example gets correctly validated (bounds checked):
vyper
x: int128 = _abi_decode(slice(msg.data, 4, 32), int128)
however, the following example is not bounds checked
vyper
@external
def abi_decode(x: uint256) -> uint256:
a: uint256 = convert(_abi_decode(slice(msg.data, 4, 32), (uint8)), uint256) + 1
return a # abi_decode(256) returns: 257
the issue can be triggered by constructing an example where the output of _abi_decode is not internally passed to make_setter (an internal codegen routine) or other input validating routine.
Patches
https://github.com/vyperlang/vyper/pull/3626
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
References
Are there any links users can visit to find out more?
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "vyper"
},
"ranges": [
{
"events": [
{
"introduced": "0.3.4"
},
{
"fixed": "0.3.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-42460"
],
"database_specific": {
"cwe_ids": [
"CWE-682"
],
"github_reviewed": true,
"github_reviewed_at": "2023-09-26T19:34:53Z",
"nvd_published_at": "2023-09-27T15:19:32Z",
"severity": "MODERATE"
},
"details": "### Impact\n`_abi_decode()` does not validate input when it is nested in an expression. the following example gets correctly validated (bounds checked):\n```vyper\nx: int128 = _abi_decode(slice(msg.data, 4, 32), int128)\n```\n\nhowever, the following example is not bounds checked\n```vyper\n@external\ndef abi_decode(x: uint256) -\u003e uint256:\n a: uint256 = convert(_abi_decode(slice(msg.data, 4, 32), (uint8)), uint256) + 1\n return a # abi_decode(256) returns: 257\n```\n\nthe issue can be triggered by constructing an example where the output of `_abi_decode` is not internally passed to `make_setter` (an internal codegen routine) or other input validating routine.\n\n### Patches\nhttps://github.com/vyperlang/vyper/pull/3626\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\n### References\n_Are there any links users can visit to find out more?_\n",
"id": "GHSA-cx2q-hfxr-rj97",
"modified": "2023-09-27T15:42:42Z",
"published": "2023-09-26T19:34:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-cx2q-hfxr-rj97"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-42460"
},
{
"type": "WEB",
"url": "https://github.com/vyperlang/vyper/pull/3626"
},
{
"type": "PACKAGE",
"url": "https://github.com/vyperlang/vyper"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Vyper\u0027s `_abi_decode` input not validated in complex expressions"
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.