{"id":"UBUNTU-CVE-2020-24659","details":"An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.","modified":"2026-04-22T12:34:53.079620Z","published":"2020-09-04T15:15:00Z","related":["USN-4491-1"],"upstream":["CVE-2020-24659"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-24659"},{"type":"REPORT","url":"https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-09-04"},{"type":"REPORT","url":"https://security.gentoo.org/glsa/202009-01"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4491-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-24659"}],"affected":[{"package":{"name":"gnutls28","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/gnutls28@3.6.13-2ubuntu1.3?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.13-2ubuntu1.3"}]}],"versions":["3.6.9-5ubuntu1","3.6.9-5ubuntu2","3.6.10-5","3.6.11.1-2","3.6.11.1-2ubuntu2","3.6.13-2ubuntu1","3.6.13-2ubuntu1.1","3.6.13-2ubuntu1.2"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"gnutls-bin","binary_version":"3.6.13-2ubuntu1.3"},{"binary_name":"guile-gnutls","binary_version":"3.6.13-2ubuntu1.3"},{"binary_name":"libgnutls-dane0","binary_version":"3.6.13-2ubuntu1.3"},{"binary_version":"3.6.13-2ubuntu1.3","binary_name":"libgnutls-openssl27"},{"binary_name":"libgnutls30","binary_version":"3.6.13-2ubuntu1.3"},{"binary_version":"3.6.13-2ubuntu1.3","binary_name":"libgnutlsxx28"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-24659.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":"medium"}]}