CVE-2020-1967
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 53.3%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
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).
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 53.34% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- openssl/openssl · debian/debian linux · freebsd/freebsd · fedoraproject/fedora · oracle/application server · oracle/enterprise manager base platform · oracle/enterprise manager for storage management · oracle/enterprise manager ops center · oracle/http server · oracle/jd edwards world security · oracle/mysql · oracle/mysql connectors · oracle/mysql enterprise monitor · oracle/mysql workbench · oracle/peoplesoft enterprise peopletools · netapp/active iq unified manager · netapp/e-series performance analyzer · netapp/oncommand insight · netapp/oncommand workflow automation · netapp/smi-s provider · +6 more
- Source
- openssl-security@openssl.org
EPSS 53.3% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.