{"id":"UBUNTU-CVE-2020-12457","details":"An issue was discovered in wolfSSL before 4.5.0. It mishandles the change_cipher_spec (CCS) message processing logic for TLS 1.3. If an attacker sends ChangeCipherSpec messages in a crafted way involving more than one in a row, the server becomes stuck in the ProcessReply() loop, i.e., a denial of service.","modified":"2026-04-22T12:27:59.825356Z","published":"2020-08-21T14:15:00Z","upstream":["CVE-2020-12457"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-12457"},{"type":"REPORT","url":"https://github.com/wolfSSL/wolfssl/pull/2927"},{"type":"REPORT","url":"https://github.com/wolfSSL/wolfssl/releases/tag/v4.5.0-stable"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-12457"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/wolfssl@3.4.8+dfsg-1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.8+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libcyassl5","binary_version":"3.4.8+dfsg-1"},{"binary_name":"libwolfssl0","binary_version":"3.4.8+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12457.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/wolfssl@3.13.0+dfsg-1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.10.2+dfsg-2","3.12.0+dfsg-1","3.12.2+dfsg-1","3.13.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libwolfssl15","binary_version":"3.13.0+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12457.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/wolfssl@4.3.0+dfsg-2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0+dfsg-2","4.2.0+dfsg-1","4.2.0+dfsg-2","4.2.0+dfsg-3","4.3.0+dfsg-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libwolfssl24","binary_version":"4.3.0+dfsg-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12457.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"low"}]}