{"id":"UBUNTU-CVE-2020-13757","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).","modified":"2026-01-30T01:39:05.830262Z","published":"2020-06-01T19:15:00Z","related":["USN-4478-1","USN-4478-2"],"upstream":["CVE-2020-13757"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-13757"},{"type":"REPORT","url":"https://github.com/sybrenstuvel/python-rsa/issues/146"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4478-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4478-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-13757"}],"affected":[{"package":{"name":"python-rsa","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/python-rsa@3.1.2-1ubuntu0.1+esm1?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.1.2-1ubuntu0.1+esm1"}]}],"versions":["3.1.2-1","3.1.2-1ubuntu0.1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"python-rsa","binary_version":"3.1.2-1ubuntu0.1+esm1"},{"binary_name":"python3-rsa","binary_version":"3.1.2-1ubuntu0.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-13757.json"}},{"package":{"name":"python-rsa","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-rsa@3.2.3-1.1ubuntu0.1~esm1?arch=source&distro=esm-apps/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.3-1.1ubuntu0.1~esm1"}]}],"versions":["3.1.4-1","3.2.3-1","3.2.3-1.1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"python-rsa","binary_version":"3.2.3-1.1ubuntu0.1~esm1"},{"binary_name":"python3-rsa","binary_version":"3.2.3-1.1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-13757.json"}},{"package":{"name":"python-rsa","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/python-rsa@3.4.2-1ubuntu0.1~esm1?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.2-1ubuntu0.1~esm1"}]}],"versions":["3.4.2-1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"python-rsa","binary_version":"3.4.2-1ubuntu0.1~esm1"},{"binary_name":"python3-rsa","binary_version":"3.4.2-1ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-13757.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}