Description
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).
Metrics
CVSS 3.1 7.5/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| OpenSSL | OpenSSL | Fixed in OpenSSL 1.1.1g (Affected 1.1.1d-1.1.1f) |
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00004.htmlMailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00011.htmlMailing List, Third Party Advisory
- http://packetstormsecurity.com/files/157527/OpenSSL-signature_algorithms_cert-Denial-Of-Service.htmlThird Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/May/5Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/04/22/2Mailing List, Third Party Advisory
- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=eb563247aef3e83dda7679c43f9649270462e5b1
- https://github.com/irsl/CVE-2020-1967Exploit, Third Party Advisory
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44440Third 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.ascPatch, Third Party Advisory
- https://security.gentoo.org/glsa/202004-10Third 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-4661Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txtVendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.htmlThird Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05_OpenSSLThird Party Advisory
- https://www.tenable.com/security/tns-2020-03Third Party Advisory
- https://www.tenable.com/security/tns-2020-04Third Party Advisory
- https://www.tenable.com/security/tns-2020-11Third Party Advisory
- https://www.tenable.com/security/tns-2021-10Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00004.htmlMailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00011.htmlMailing List, Third Party Advisory
- http://packetstormsecurity.com/files/157527/OpenSSL-signature_algorithms_cert-Denial-Of-Service.htmlThird Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/May/5Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/04/22/2Mailing List, Third Party Advisory
- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=eb563247aef3e83dda7679c43f9649270462e5b1
- https://github.com/irsl/CVE-2020-1967Exploit, Third Party Advisory
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44440Third 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.ascPatch, Third Party Advisory
- https://security.gentoo.org/glsa/202004-10Third 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-4661Third Party Advisory
- https://www.openssl.org/news/secadv/20200421.txtVendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.htmlThird Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05Third Party Advisory
- https://www.synology.com/security/advisory/Synology_SA_20_05_OpenSSLThird Party Advisory
Timeline
- Published
- Apr 21, 2020
- Last modified
- Oct 8, 2026
- NVD status
- Modified