{
"id": "GHSA-vqgp-4jgj-5j64",
"aliases": [
"CVE-2018-18920"
],
"details": "Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers computation._stack.values with '\"stack\": [100, 100, 0]' where b'\\x' was expected, resulting in an execution failure because of an invalid opcode. This is reportedly related to \"smart contracts can be executed indefinitely without gas being paid.\"",
"summary": "Py-EVM is vulnerable to arbitrary bytecode injection",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"last_affected": "0.2.0a33"
}
]
}
],
"package": {
"name": "py-evm",
"ecosystem": "PyPI"
}
}
],
"modified": "2026-06-05T17:53:32Z",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
}
],
"published": "2018-11-21T22:23:04Z",
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-18920",
"type": "ADVISORY"
},
{
"url": "https://github.com/ethereum/py-evm/issues/1448",
"type": "WEB"
},
{
"url": "https://github.com/advisories/GHSA-vqgp-4jgj-5j64",
"type": "ADVISORY"
},
{
"url": "https://github.com/ethereum/py-evm",
"type": "PACKAGE"
},
{
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/evm-py/PYSEC-2018-155.yaml",
"type": "WEB"
},
{
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/py-evm/PYSEC-2018-96.yaml",
"type": "WEB"
},
{
"url": "https://twitter.com/AlexanderFisher/status/1060923428641878019",
"type": "WEB"
},
{
"url": "https://twitter.com/NettaLab/status/1060889400102383617",
"type": "WEB"
},
{
"url": "https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-119"
],
"severity": "HIGH",
"github_reviewed": true,
"nvd_published_at": null,
"github_reviewed_at": "2020-06-16T21:58:10Z"
}
}