{"id":"CVE-2023-23940","aliases":["EUVD-2023-0188","GHSA-626q-v9j4-mcp4","PYSEC-2023-39"],"status":"published","title":"OpenZeppelin Contracts for Cairo is vulnerable to signature validation bypass","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.","severity":{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.0022,"percentile":0.12638,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-345","CWE-347"],"published":"2023-02-02T16:59:46Z","modified":"2026-10-28T02:30:33Z","fixes":[{"ecosystem":"PyPI","package":"openzeppelin-cairo-contracts","fixed_in":["0.6.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"openzeppelin-cairo-contracts","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.2.0"},{"fixed":"0.6.1"}]}]},{"source":"osv","ecosystem":"PyPI","package":"openzeppelin-cairo-contracts","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.2.0"},{"fixed":"0.6.1"}]}],"versions":["0.2.0","0.2.1","0.3.0","0.3.1","0.3.2","0.4.0","0.4.0b0","0.5.0","0.5.1","0.6.0"]},{"source":"osv","ecosystem":"PyPI","package":"openzeppelin-cairo-contracts","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"6d4cb750478fca2fd916f73297632f899aca9299"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0.2.0"},{"fixed":"0.6.1"}]}],"versions":["0.2.0","0.2.1","0.3.0","0.3.1","0.3.2","0.4.0","0.4.0b0","0.5.0","0.5.1","0.6.0"]}],"products":[{"vendor":"openzeppelin","product":"cairo-contracts"},{"vendor":"openzeppelin","product":"contracts"}],"references":[{"url":"https://github.com/OpenZeppelin/cairo-contracts/security/advisories/GHSA-626q-v9j4-mcp4","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/OpenZeppelin/cairo-contracts/pull/542/commits/6d4cb750478fca2fd916f73297632f899aca9299","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","web","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-23940","tags":["advisory"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/openzeppelin-cairo-contracts/PYSEC-2023-39.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-626q-v9j4-mcp4"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/23xxx/CVE-2023-23940.json","tags":["advisory"]},{"url":"https://github.com/OpenZeppelin/cairo-contracts","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-23940","title":"OpenZeppelin Contracts for Cairo is vulnerable to signature validation bypass","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.\n","status":"published","published":"2023-02-03T19:43:11.178Z","modified":"2025-03-10T21:16:55.772Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-347","CWE-345"],"updated_at":"2026-11-02T14:35:20.812737Z"}],"euvd":[{"id":"EUVD-2023-0188","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.\n","status":"published","published":"2023-02-03T19:43:11Z","modified":"2025-03-10T21:16:55Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium"}],"updated_at":"2026-11-02T20:53:08.584552Z"}],"ghsa":[{"id":"GHSA-626q-v9j4-mcp4","title":"OpenZeppelin Contracts contains Improper Verification of Cryptographic Signature","description":"### Cause\n`is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. \n\n### Impact\nAs a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts.\n\n### Risk\nIn order to exploit this vulnerability, it is required to control a sequencer or prover since they're the ones executing the hints, being able to inject incorrect keccak results.\n\nToday StarkWare is the only party running both a prover or a sequencer, greatly reducing the risk of exploit.\n\n### Patches\nThe issue has been patched in 0.6.1.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [the Contracts for Cairo repository](https://github.com/OpenZeppelin/cairo-contracts/issues/new/choose)\n* Email us at [security@openzeppelin.com](mailto:security@openzeppelin.com)","status":"published","published":"2023-02-02T16:59:46Z","modified":"2024-10-07T21:19:34Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T14:38:08.742903Z"}],"nvd":[{"id":"CVE-2023-23940","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.\n","status":"published","published":"2023-02-03T20:15:11.037Z","modified":"2026-06-17T05:38:20.13Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T14:07:46.064662Z"}],"osv":[{"id":"CVE-2023-23940","title":"OpenZeppelin Contracts for Cairo is vulnerable to signature validation bypass","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.\n","status":"published","published":"2023-02-03T19:43:11.178Z","modified":"2026-10-28T02:30:33.781155979Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T15:44:30.709518Z"},{"id":"GHSA-626q-v9j4-mcp4","title":"OpenZeppelin Contracts contains Improper Verification of Cryptographic Signature","description":"### Cause\n`is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. \n\n### Impact\nAs a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts.\n\n### Risk\nIn order to exploit this vulnerability, it is required to control a sequencer or prover since they're the ones executing the hints, being able to inject incorrect keccak results.\n\nToday StarkWare is the only party running both a prover or a sequencer, greatly reducing the risk of exploit.\n\n### Patches\nThe issue has been patched in 0.6.1.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [the Contracts for Cairo repository](https://github.com/OpenZeppelin/cairo-contracts/issues/new/choose)\n* Email us at [security@openzeppelin.com](mailto:security@openzeppelin.com)","status":"published","published":"2023-02-02T16:59:46Z","modified":"2026-02-22T22:56:17.554616Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"},{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-345","CWE-347"],"updated_at":"2026-11-02T15:46:38.911014Z"},{"id":"PYSEC-2023-39","description":"OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.","status":"published","published":"2023-02-03T20:15:00Z","modified":"2026-02-22T22:49:15.001963Z","updated_at":"2026-11-02T15:52:53.837392Z"}]}}