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).
Fix
Public exploits 1
- irsl/CVE-2020-1967 PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Patch, vendor advisory and mitigation references on NVD 14
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc Patch, Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txt Vendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.html Patch, Third Party Advisory
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc Patch, Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txt Vendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.html Patch, Third Party Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · openssl, debian, freebsdNVD modified 2026-10-08 21:17
Affected (CPE criteria) 35
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*cpe:2.3:o:freebsd:freebsd:12.1:-:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*cpe:2.3:a:oracle:application_server:12.1.3:*:*:*:*:*:*:*cpe:2.3:a:oracle:enterprise_manager_base_platform:13.4.0.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:enterprise_manager_for_storage_management:13.3.0.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:enterprise_manager_for_storage_management:13.4.0.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:jd_edwards_world_security:a9.4:*:*:*:*:*:*:*cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*cpe:2.3:a:oracle:mysql_connectors:*:*:*:*:*:*:*:*cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*cpe:2.3:a:oracle:mysql_workbench:*:*:*:*:*:*:*:*cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.56:*:*:*:*:*:*:*cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:*:*:*:*:*:*:*cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.58:*:*:*:*:*:*:*cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.59:*:*:*:*:*:*:*cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:windows:*:*cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:vmware_vsphere:*:*cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:smi-s_provider:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:steelstore_cloud_integrated_storage:-:*:*:*:*:*:*:*cpe:2.3:o:broadcom:fabric_operating_system:-:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*cpe:2.3:a:jdedwards:enterpriseone:*:*:*:*:*:*:*:*cpe:2.3:a:tenable:log_correlation_engine:*:*:*:*:*:*:*:*
References 64
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00004.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00011.html Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/157527/OpenSSL-signature_algorithms_cert-Denial-Of-Service.html Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/May/5 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/04/22/2 Mailing List, Third Party Advisory
- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=eb563247aef3e83dda7679c43f9649270462e5b1
- https://github.com/irsl/CVE-2020-1967 Exploit, Third Party Advisory
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44440 Third Party Advisory
- https://lists.apache.org/thread.html/r66ea9c436da150683432db5fbc8beb8ae01886c6459ac30c2cea7345%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r94d6ac3f010a38fccf4f432b12180a13fa1cf303559bd805648c9064%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9a41e304992ce6aec6585a87842b4f2e692604f5c892c37e3b0587ee%40%3Cdev.tomcat.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc Patch, Third Party Advisory
- https://security.gentoo.org/glsa/202004-10 Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200424-0003/ Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200717-0004/ Third Party Advisory
- https://www.debian.org/security/2020/dsa-4661 Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txt Vendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.html Patch, Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05 Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05_OpenSSL Third Party Advisory
- https://www.tenable.com/security/tns-2020-03 Third Party Advisory
- https://www.tenable.com/security/tns-2020-04 Third Party Advisory
- https://www.tenable.com/security/tns-2020-11 Third Party Advisory
- https://www.tenable.com/security/tns-2021-10 Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00004.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00011.html Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/157527/OpenSSL-signature_algorithms_cert-Denial-Of-Service.html Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/May/5 Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/04/22/2 Mailing List, Third Party Advisory
- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=eb563247aef3e83dda7679c43f9649270462e5b1
- https://github.com/irsl/CVE-2020-1967 Exploit, Third Party Advisory
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44440 Third Party Advisory
- https://lists.apache.org/thread.html/r66ea9c436da150683432db5fbc8beb8ae01886c6459ac30c2cea7345%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r94d6ac3f010a38fccf4f432b12180a13fa1cf303559bd805648c9064%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9a41e304992ce6aec6585a87842b4f2e692604f5c892c37e3b0587ee%40%3Cdev.tomcat.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc Patch, Third Party Advisory
- https://security.gentoo.org/glsa/202004-10 Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200424-0003/ Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200717-0004/ Third Party Advisory
- https://www.debian.org/security/2020/dsa-4661 Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txt Vendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.html Patch, Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05 Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05_OpenSSL Third Party Advisory