{"id":"CVE-2020-13757","aliases":["GHSA-537h-rv9q-vvph","PYSEC-2020-99"],"url":"https://o3.security/vulnerability/CVE-2020-13757","summary":"Python-RSA decryption of ciphertext leads to DoS","details":"Python-RSA before 4.1 ignores leading '\\0' bytes during decryption of ciphertext. This could conceivably have a security-relevant impact, e.g., by helping an attacker to infer that an application uses Python-RSA, or if the length of accepted ciphertext affects application behavior (such as by causing excessive memory allocation).","published":"2020-06-01T19:15:10.067Z","modified":"2026-07-08T05:56:02.110909196Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"PyPI","name":"rsa","fixedVersion":"4.1"}],"fix":null,"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KILTHBHNSDUCYV22ODLOKTICJJ7JQIQ/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZYB65VNILRBTXL6EITQTH2PZPK7I23MW/"},{"type":"ADVISORY","url":"https://usn.ubuntu.com/4478-1/"},{"type":"REPORT","url":"https://github.com/sybrenstuvel/python-rsa/issues/146"},{"type":"REPORT","url":"https://github.com/sybrenstuvel/python-rsa/issues/146#issuecomment-641845667"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-13757"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/rsa/PYSEC-2020-99.yaml"},{"type":"PACKAGE","url":"https://github.com/sybrenstuvel/python-rsa"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2KILTHBHNSDUCYV22ODLOKTICJJ7JQIQ"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZYB65VNILRBTXL6EITQTH2PZPK7I23MW"},{"type":"WEB","url":"https://usn.ubuntu.com/4478-1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T05:56:02.110909196Z"}}