Segmentation fault in SSL_check_chain

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Summary

CVECVE-2020-1967
StatePUBLISHED
Assigneropenssl
Source PriorityCVE Program / NVD first with legacy fallback
Published2020-04-21 14:15:11 UTC
Updated2026-10-08 21:17:24 UTC
DescriptionServer 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).

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.533360000 probability, percentile 0.989640000 (date 2026-10-10)

Problem Types: CWE-476 | NULL pointer dereference

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2.0[email protected]Primary5AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Broadcom Fabric Operating System - All All All
Operating System Debian Debian Linux 10.0 All All All
Operating System Debian Debian Linux 9.0 All All All
Operating System Fedoraproject Fedora 30 All All All
Operating System Fedoraproject Fedora 31 All All All
Operating System Fedoraproject Fedora 32 All All All
Operating System Freebsd Freebsd 12.1 - All All
Application Jdedwards Enterpriseone All All All All
Application Netapp Active Iq Unified Manager All All All All
Application Netapp Active Iq Unified Manager All All All All
Application Netapp E-series Performance Analyzer - All All All
Application Netapp Oncommand Insight - All All All
Application Netapp Oncommand Workflow Automation - All All All
Application Netapp Smi-s Provider - All All All
Application Netapp Snapcenter - All All All
Application Netapp Steelstore Cloud Integrated Storage - All All All
Application Openssl Openssl All All All All
Operating System Opensuse Leap 15.1 All All All
Operating System Opensuse Leap 15.2 All All All
Application Oracle Application Server 12.1.3 All All All
Application Oracle Enterprise Manager Base Platform 13.4.0.0 All All All
Application Oracle Enterprise Manager For Storage Management 13.3.0.0 All All All
Application Oracle Enterprise Manager For Storage Management 13.4.0.0 All All All
Application Oracle Enterprise Manager Ops Center 12.4.0 All All All
Application Oracle Http Server 12.2.1.4.0 All All All
Application Oracle Jd Edwards World Security a9.4 All All All
Application Oracle Mysql All All All All
Application Oracle Mysql All All All All
Application Oracle Mysql All All All All
Application Oracle Mysql Connectors All All All All
Application Oracle Mysql Enterprise Monitor All All All All
Application Oracle Mysql Enterprise Monitor All All All All
Application Oracle Mysql Workbench All All All All
Application Oracle Peoplesoft Enterprise Peopletools 8.56 All All All
Application Oracle Peoplesoft Enterprise Peopletools 8.57 All All All
Application Oracle Peoplesoft Enterprise Peopletools 8.58 All All All
Application Oracle Peoplesoft Enterprise Peopletools 8.59 All All All
Application Tenable Log Correlation Engine All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA OpenSSL OpenSSL affected Fixed in OpenSSL 1.1.1g (Affected 1.1.1d-1.1.1f) Not specified

References

ReferenceSourceLinkTags
oss-security - [CVE-2020-1967] OpenSSL 1.1.1d+ Segmentation fault in SSL_check_chain af854a3a-2127-422b-91ae-364da2661108 www.openwall.com Mailing List, Third Party Advisory
OpenSSL signature_algorithms_cert Denial Of Service ≈ Packet Storm af854a3a-2127-422b-91ae-364da2661108 packetstormsecurity.com Third Party Advisory, VDB Entry
[SECURITY] Fedora 30 Update: openssl-1.1.1g-1.fc30 - package-announce - Fedora Mailing-Lists af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
CVE-2020-1967 OpenSSL Vulnerability in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
Oracle Critical Patch Update Advisory - October 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
www.openssl.org/news/secadv/20200421.txt af854a3a-2127-422b-91ae-364da2661108 www.openssl.org Vendor Advisory
git.openssl.org Git - openssl.git/commitdiff af854a3a-2127-422b-91ae-364da2661108 git.openssl.org
Oracle Critical Patch Update Advisory - July 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
OpenSSL: Multiple vulnerabilities (GLSA 202004-10) — Gentoo security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org Third Party Advisory
Oracle Critical Patch Update Advisory - January 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Debian -- Security Information -- DSA-4661-1 openssl af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
[R1] Nessus Agent 7.6.3 Fixes Multiple Third-party Vulnerabilities - Security Advisory | Tenable® af854a3a-2127-422b-91ae-364da2661108 www.tenable.com Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - April 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Oracle Critical Patch Update Advisory - October 2020 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
[security-announce] openSUSE-SU-2020:0945-1: moderate: Security update f af854a3a-2127-422b-91ae-364da2661108 lists.opensuse.org Mailing List, Third Party Advisory
[SECURITY] Fedora 31 Update: openssl-1.1.1g-1.fc31 - package-announce - Fedora Mailing-Lists af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
[R1] LCE 6.0.9 Fixes Multiple Third-party Vulnerabilities - Security Advisory | Tenable® af854a3a-2127-422b-91ae-364da2661108 www.tenable.com Third Party Advisory
security.FreeBSD.org/advisories/FreeBSD-SA-20:11.openssl.asc af854a3a-2127-422b-91ae-364da2661108 security.FreeBSD.org Patch, Third Party Advisory
Synology Inc. af854a3a-2127-422b-91ae-364da2661108 www.synology.com Third Party Advisory
July 2020 MySQL Vulnerabilities in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
[R1] Tenable.sc 5.17.0 Fixes Multiple Vulnerabilities - Security Advisory | Tenable® af854a3a-2127-422b-91ae-364da2661108 www.tenable.com Third Party Advisory
Full Disclosure: CVE-2020-1967: proving sigalg != NULL af854a3a-2127-422b-91ae-364da2661108 seclists.org Mailing List, Third Party Advisory
[SECURITY] Fedora 32 Update: openssl-1.1.1g-1.fc32 - package-announce - Fedora Mailing-Lists af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
[R1] Nessus Network Monitor 5.11.1 Fixes One Third-party Vulnerability - Security Advisory | Tenable® af854a3a-2127-422b-91ae-364da2661108 www.tenable.com Third Party Advisory
Synology Inc. af854a3a-2127-422b-91ae-364da2661108 www.synology.com Third Party Advisory
GitHub - irsl/CVE-2020-1967: Proof of concept exploit about OpenSSL signature_algorithms_cert DoS flaw (CVE-2020-1967) af854a3a-2127-422b-91ae-364da2661108 github.com Exploit, Third Party Advisory
Oracle Critical Patch Update Advisory - July 2020 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Third Party Advisory
[security-announce] openSUSE-SU-2020:0933-1: moderate: Security update f af854a3a-2127-422b-91ae-364da2661108 lists.opensuse.org Mailing List, Third Party Advisory
Public KB - SA44440 - April 21 2020 OpenSSL Security Advisory af854a3a-2127-422b-91ae-364da2661108 kb.pulsesecure.net Third Party Advisory
git.openssl.org Git - openssl.git/commitdiff MITRE git.openssl.org
[SECURITY] Fedora 31 Update: openssl-1.1.1g-1.fc31 - package-announce - Fedora Mailing-Lists MITRE lists.fedoraproject.org
[SECURITY] Fedora 30 Update: openssl-1.1.1g-1.fc30 - package-announce - Fedora Mailing-Lists MITRE lists.fedoraproject.org
[SECURITY] Fedora 32 Update: openssl-1.1.1g-1.fc32 - package-announce - Fedora Mailing-Lists MITRE lists.fedoraproject.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Bernd Edlinger (en)

Legacy QID Mappings

  • 296072 Oracle Solaris 11.4 Support Repository Update (SRU) 25.75.3 Missing (CPUJUL2020)
  • 375970 Oracle PeopleSoft Enterprise PeopleTools Product Multiple Vulnerabilities (CPUOCT2021)
  • 500495 Alpine Linux Security Update for Open Secure Sockets Layer (OpenSSL)
  • 500563 Alpine Linux Security Update for Open Secure Sockets Layer (OpenSSL)
  • 500762 Alpine Linux Security Update for openssl
  • 501162 Alpine Linux Security Update for openssl
  • 501981 Alpine Linux Security Update for Open Secure Sockets Layer3 (OpenSSL3)
  • 502900 Alpine Linux Security Update for openssl1.1-compat
  • 504254 Alpine Linux Security Update for openssl
  • 690571 Free Berkeley Software Distribution (FreeBSD) Security Update for Open Secure Sockets Layer (OpenSSL) remote Denial of Service (DoS) Vulnerability (012809ce-83f3-11ea-92ab-00163e433440)

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