{"id":"UBUNTU-CVE-2021-40529","details":"The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.","modified":"2026-04-22T13:01:45.484093Z","published":"2021-09-06T19:15:00Z","upstream":["CVE-2021-40529"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-40529"},{"type":"REPORT","url":"https://eprint.iacr.org/2021/923"},{"type":"REPORT","url":"https://github.com/randombit/botan/pull/2790"},{"type":"REPORT","url":"https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1"},{"type":"REPORT","url":"https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-40529"}],"affected":[{"package":{"name":"botan1.10","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/botan1.10@1.10.5-1+deb7u1ubuntu0.14.04.1+esm1?arch=source&distro=esm-infra-legacy/trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-1","1.10.5-1ubuntu1","1.10.5-1+deb7u1ubuntu0.14.04.1","1.10.5-1+deb7u1ubuntu0.14.04.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libbotan-1.10-0","binary_version":"1.10.5-1+deb7u1ubuntu0.14.04.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}},{"package":{"name":"botan1.10","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/botan1.10@1.10.12-1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.10-6","1.10.12-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libbotan-1.10-1","binary_version":"1.10.12-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}},{"package":{"name":"botan","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/botan@2.4.0-5ubuntu1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.0-3","2.4.0-4","2.4.0-5ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"botan","binary_version":"2.4.0-5ubuntu1"},{"binary_name":"libbotan-2-4","binary_version":"2.4.0-5ubuntu1"},{"binary_name":"python3-botan","binary_version":"2.4.0-5ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}},{"package":{"name":"botan1.10","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/botan1.10@1.10.17-0.1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.16-1","1.10.17-0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libbotan-1.10-1","binary_version":"1.10.17-0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}},{"package":{"name":"botan","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/botan@2.12.1-2build1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.9.0-2","2.9.0-2build1","2.12.1-2","2.12.1-2build1"],"ecosystem_specific":{"binaries":[{"binary_name":"botan","binary_version":"2.12.1-2build1"},{"binary_name":"libbotan-2-12","binary_version":"2.12.1-2build1"},{"binary_version":"2.12.1-2build1","binary_name":"python3-botan"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}},{"package":{"name":"botan","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/botan@2.19.1+dfsg-2ubuntu1+esm1?arch=source&distro=esm-apps/jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.3+dfsg-3","2.19.1+dfsg-2ubuntu1","2.19.1+dfsg-2ubuntu1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"botan","binary_version":"2.19.1+dfsg-2ubuntu1+esm1"},{"binary_name":"libbotan-2-19","binary_version":"2.19.1+dfsg-2ubuntu1+esm1"},{"binary_version":"2.19.1+dfsg-2ubuntu1+esm1","binary_name":"python3-botan"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40529.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"low"}]}