{"id":"CVE-2023-39363","summary":"Vyper incorrectly allocated named re-entrancy locks","details":"Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In versions 0.2.15, 0.2.16 and 0.3.0, named re-entrancy locks are allocated incorrectly. Each function using a named re-entrancy lock gets a unique lock regardless of the key, allowing cross-function re-entrancy in contracts compiled with the susceptible versions. A specific set of conditions is required to result in misbehavior of affected contracts, specifically: a `.vy` contract compiled with `vyper` versions `0.2.15`, `0.2.16`, or `0.3.0`; a primary function that utilizes the `@nonreentrant` decorator with a specific `key` and does not strictly follow the check-effects-interaction pattern (i.e. contains an external call to an untrusted party before storage updates); and a secondary function that utilizes the same `key` and would be affected by the improper state caused by the primary function. Version 0.3.1 contains a fix for this issue.","aliases":["GHSA-5824-cm3x-3c38","PYSEC-2023-142"],"modified":"2026-08-12T03:51:34.634470614Z","published":"2023-08-07T18:40:25.615Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39363.json"},"references":[{"type":"WEB","url":"https://hackmd.io/@LlamaRisk/BJzSKHNjn"},{"type":"WEB","url":"https://hackmd.io/@vyperlang/HJUgNMhs2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39363.json"},{"type":"ADVISORY","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-5824-cm3x-3c38"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-39363"},{"type":"FIX","url":"https://github.com/vyperlang/vyper/pull/2439"},{"type":"FIX","url":"https://github.com/vyperlang/vyper/pull/2514"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/vyperlang/vyper","events":[{"introduced":"6e7dba7a8b5f29762d3470da4f44634b819c808d"},{"last_affected":"8a23febbb2d523f3701f9a7d0aaf361c104a2a37"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_STRING"],"cpe":["cpe:2.3:a:vyperlang:vyper:0.2.15:*:*:*:*:python:*:*","cpe:2.3:a:vyperlang:vyper:0.2.16:*:*:*:*:python:*:*","cpe:2.3:a:vyperlang:vyper:0.3.0:*:*:*:*:python:*:*"],"extracted_events":[{"introduced":"= 0.2.15"},{"last_affected":"= 0.2.15"},{"introduced":"= 0.2.16"},{"last_affected":"= 0.2.16"},{"introduced":"= 0.3.0"},{"last_affected":"= 0.3.0"},{"introduced":"0.2.15"},{"last_affected":"0.2.15"},{"introduced":"0.2.16"},{"last_affected":"0.2.16"},{"introduced":"0.3.0"},{"last_affected":"0.3.0"}]}}],"versions":["0.2.15","0.2.16","0.3.0","= 0.2.15","= 0.2.16","= 0.3.0","v0.3.0","v0.2.16","v0.2.15"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-39363.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:A"}]}