{"id":"CVE-2020-1967","aliases":["GHSA-jq65-29v4-4x35","RUSTSEC-2020-0015"],"url":"https://o3.security/vulnerability/CVE-2020-1967","summary":"Null pointer deference in openssl-src ","details":"Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the \"signature_algorithms_cert\" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm is received from the peer. This could be exploited by a malicious peer in a Denial of Service attack. OpenSSL version 1.1.1d, 1.1.1e, and 1.1.1f are affected by this issue. This issue did not affect OpenSSL versions prior to 1.1.1d. Fixed in OpenSSL 1.1.1g (Affected 1.1.1d-1.1.1f).","published":"2020-04-21T14:15:11.287Z","modified":"2026-10-10T02:45:31.408608423Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.53336,"percentile":0.98907,"asOf":"2026-08-30"},"cisaKev":null,"exploitsKnown":3,"affectedPackages":[{"ecosystem":"crates.io","name":"openssl-src","fixedVersion":"111.9.0"}],"fix":null,"references":[{"type":"WEB","url":"https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=eb563247aef3e83dda7679c43f9649270462e5b1"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r66ea9c436da150683432db5fbc8beb8ae01886c6459ac30c2cea7345%40%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r94d6ac3f010a38fccf4f432b12180a13fa1cf303559bd805648c9064%40%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r9a41e304992ce6aec6585a87842b4f2e692604f5c892c37e3b0587ee%40%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/"},{"type":"ADVISORY","url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00004.html"},{"type":"ADVISORY","url":"http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00011.html"},{"type":"ADVISORY","url":"http://packetstormsecurity.com/files/157527/OpenSSL-signature_algorithms_cert-Denial-Of-Service.html"},{"type":"ADVISORY","url":"http://seclists.org/fulldisclosure/2020/May/5"},{"type":"ADVISORY","url":"http://www.openwall.com/lists/oss-security/2020/04/22/2"},{"type":"ADVISORY","url":"https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44440"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202004-10"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20200424-0003/"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20200717-0004/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2020/dsa-4661"},{"type":"ADVISORY","url":"https://www.openssl.org/news/secadv/20200421.txt"},{"type":"ADVISORY","url":"https://www.oracle.com/security-alerts/cpujul2020.html"},{"type":"ADVISORY","url":"https://www.synology.com/security/advisory/Synology_SA_20_05"},{"type":"ADVISORY","url":"https://www.synology.com/security/advisory/Synology_SA_20_05_OpenSSL"},{"type":"ADVISORY","url":"https://www.tenable.com/security/tns-2020-03"},{"type":"ADVISORY","url":"https://www.tenable.com/security/tns-2020-04"},{"type":"ADVISORY","url":"https://www.tenable.com/security/tns-2020-11"},{"type":"ADVISORY","url":"https://www.tenable.com/security/tns-2021-10"},{"type":"FIX","url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc"},{"type":"FIX","url":"https://www.oracle.com//security-alerts/cpujul2021.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuApr2021.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujan2021.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuoct2020.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuoct2021.html"},{"type":"EVIDENCE","url":"https://github.com/irsl/CVE-2020-1967"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-1967"},{"type":"WEB","url":"https://security.netapp.com/advisory/ntap-20200717-0004"},{"type":"WEB","url":"https://security.netapp.com/advisory/ntap-20200424-0003"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2020-0015.html"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r9a41e304992ce6aec6585a87842b4f2e692604f5c892c37e3b0587ee@%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r94d6ac3f010a38fccf4f432b12180a13fa1cf303559bd805648c9064@%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r66ea9c436da150683432db5fbc8beb8ae01886c6459ac30c2cea7345@%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=eb563247aef3e83dda7679c43f9649270462e5b1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-10T02:45:31.408608423Z"}}