{"id":"UBUNTU-CVE-2024-1544","details":"Generating the ECDSA nonce k samples a random number r and then truncates this randomness with a modular reduction mod n where n is the order of the elliptic curve. Meaning k = r mod n. The division used during the reduction estimates a factor q_e by dividing the upper two digits (a digit having e.g. a size of 8 byte) of r by the upper digit of n and then decrements q_e in a loop until it has the correct size. Observing the number of times q_e is decremented through a control-flow revealing side-channel reveals a bias in the most significant bits of k. Depending on the curve this is either a negligible bias or a significant bias large enough to reconstruct k with lattice reduction methods. For SECP160R1, e.g., we find a bias of 15 bits.","modified":"2026-05-20T16:16:31.213916969Z","published":"2024-08-27T19:15:00Z","upstream":["CVE-2024-1544"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2024-1544"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2024-1544"},{"type":"REPORT","url":"https://github.com/wolfSSL/wolfssl/releases/tag/v5.7.2-stable"},{"type":"REPORT","url":"https://github.com/wolfSSL/wolfssl/pull/7020"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.8+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.8+dfsg-1","binary_name":"libcyassl5"},{"binary_version":"3.4.8+dfsg-1","binary_name":"libwolfssl0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?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/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?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/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.6.0-3","5.0.0-1","5.1.1-1","5.2.0-1","5.2.0-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libwolfssl32","binary_version":"5.2.0-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.5.4-2","5.5.4-2.1","5.6.4-2","5.6.6-1.2","5.6.6-1.3","5.6.6-1.3build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libwolfssl42t64","binary_version":"5.6.6-1.3build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/wolfssl?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.7.2-0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.7.2-0.1","binary_name":"libwolfssl42t64"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-1544.json"}},{"package":{"name":"wolfssl","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/wolfssl?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.7.2-0.1","5.8.2-1.2","5.8.4-1","5.9.1-0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.9.1-0.1","binary_name":"libwolfssl44"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-1544.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}