{"id":"PYSEC-2020-42","details":"An issue was discovered in fastecdsa before 2.1.2. When using the NIST P-256 curve in the ECDSA implementation, the point at infinity is mishandled. This means that for an extreme value in k and s^-1, the signature verification fails even if the signature is correct. This behavior is not solely a usability problem. There are some threat models where an attacker can benefit by successfully guessing users for whom signature verification will fail.","aliases":["CVE-2020-12607","GHSA-56wv-2wr9-3h9r"],"modified":"2023-11-08T04:02:10.552763Z","published":"2020-06-02T21:15:00Z","references":[{"type":"FIX","url":"https://github.com/AntonKueltz/fastecdsa/commit/4a16daeaf139be20654ef58a9fe4c79dc030458c"},{"type":"FIX","url":"https://github.com/AntonKueltz/fastecdsa/commit/7b64e3efaa806b4daaf73bb5172af3581812f8de"},{"type":"REPORT","url":"https://github.com/AntonKueltz/fastecdsa/issues/52"},{"type":"FIX","url":"https://github.com/AntonKueltz/fastecdsa/commit/e592f106edd5acf6dacedfab2ad16fe6c735c9d1"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-56wv-2wr9-3h9r"}],"affected":[{"package":{"name":"fastecdsa","ecosystem":"PyPI","purl":"pkg:pypi/fastecdsa"},"ranges":[{"type":"GIT","repo":"https://github.com/AntonKueltz/fastecdsa","events":[{"introduced":"0"},{"fixed":"4a16daeaf139be20654ef58a9fe4c79dc030458c"},{"fixed":"7b64e3efaa806b4daaf73bb5172af3581812f8de"},{"fixed":"e592f106edd5acf6dacedfab2ad16fe6c735c9d1"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.2"}]}],"versions":["1.0.0b1","1.0.1b1","1.0.1b2","1.0.1b3","1.0.1","1.0.2","1.0.3","1.1.0","1.1.1","1.1.2","1.1.3","1.2.1","1.3.1","1.3.2","1.4.1","1.4.2","1.4.3","1.5.1","1.5.2","1.6.1","1.6.2","1.6.3","1.6.4","1.6.5","1.7.0","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","2.0.0","2.1.0","2.1.1"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/fastecdsa/PYSEC-2020-42.yaml"}}],"schema_version":"1.7.3"}