{"id":"UBUNTU-CVE-2020-12403","details":"A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.","modified":"2026-04-22T12:28:14.903967Z","published":"2020-08-18T03:55:00Z","related":["USN-4476-1"],"upstream":["CVE-2020-12403"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-12403"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2020-12403"},{"type":"REPORT","url":"https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.55_release_notes"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4476-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-12403"}],"affected":[{"package":{"name":"nss","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/nss@2:3.28.4-0ubuntu0.14.04.5+esm8?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.28.4-0ubuntu0.14.04.5+esm8"}]}],"versions":["2:3.15.1-1ubuntu1","2:3.15.2-1","2:3.15.3-1","2:3.15.3.1-1","2:3.15.3.1-1.1","2:3.15.3.1-1.1ubuntu1","2:3.15.4-1ubuntu3","2:3.15.4-1ubuntu4","2:3.15.4-1ubuntu5","2:3.15.4-1ubuntu6","2:3.15.4-1ubuntu7","2:3.15.4-1ubuntu7.1","2:3.17-0ubuntu0.14.04.1","2:3.17.1-0ubuntu0.14.04.1","2:3.17.1-0ubuntu0.14.04.2","2:3.17.4-0ubuntu0.14.04.1","2:3.19.2-0ubuntu0.14.04.1","2:3.19.2.1-0ubuntu0.14.04.1","2:3.19.2.1-0ubuntu0.14.04.2","2:3.21-0ubuntu0.14.04.1","2:3.21-0ubuntu0.14.04.2","2:3.23-0ubuntu0.14.04.1","2:3.26.2-0ubuntu0.14.04.3","2:3.28.4-0ubuntu0.14.04.1","2:3.28.4-0ubuntu0.14.04.2","2:3.28.4-0ubuntu0.14.04.3","2:3.28.4-0ubuntu0.14.04.4","2:3.28.4-0ubuntu0.14.04.5","2:3.28.4-0ubuntu0.14.04.5+esm1","2:3.28.4-0ubuntu0.14.04.5+esm2","2:3.28.4-0ubuntu0.14.04.5+esm3","2:3.28.4-0ubuntu0.14.04.5+esm4","2:3.28.4-0ubuntu0.14.04.5+esm5","2:3.28.4-0ubuntu0.14.04.5+esm6","2:3.28.4-0ubuntu0.14.04.5+esm7"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): 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subscription required","binaries":[{"binary_name":"libnss3","binary_version":"2:3.35-2ubuntu2.12"},{"binary_name":"libnss3-tools","binary_version":"2:3.35-2ubuntu2.12"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12403.json"}},{"package":{"name":"nss","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/nss@2:3.49.1-1ubuntu1.5?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:3.49.1-1ubuntu1.5"}]}],"versions":["2:3.45-1ubuntu2","2:3.47-1ubuntu1","2:3.47-1ubuntu2","2:3.48-1ubuntu1","2:3.49.1-1ubuntu1","2:3.49.1-1ubuntu1.1","2:3.49.1-1ubuntu1.2","2:3.49.1-1ubuntu1.4"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libnss3","binary_version":"2:3.49.1-1ubuntu1.5"},{"binary_version":"2:3.49.1-1ubuntu1.5","binary_name":"libnss3-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12403.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:H/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}