CVE-2020-1967 | Segmentation fault in SSL_check_chain

Exp

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: 2020-04-21 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-1967 is rated High Exploit Risk (74.4/100): CVSS High severity, with high exploitation likelihood (EPSS 60.77%, 98th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-1967

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-1967

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-20 67.31% 60.77% -6.54%
2 2026-03-23 64.69% 67.31% +2.62%
3 2026-03-04 — 64.69% —

Full EPSS history (58 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-1967

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-1967

GitHub Security Advisory for CVE-2020-1967

GHSA-jq65-29v4-4x35 · Severity: high · Ecosystem: rust — Null pointer deference in openssl-src

OS Trackers for CVE-2020-1967

vendor priority summary link
alpine high CVE-2020-1967: 3 source package rows (openssl, openssl1.1-compat, openssl3); 25 state rows across 13 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.17-main, 3.18-community, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-community, edge-main); fixed 15, open 10. https://security.alpinelinux.org/vuln/CVE-2020-1967
debian not yet assigned CVE-2020-1967 not yet assigned priority: Debian including 1 source packages (openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-1967
gentoo normal CVE-2020-1967: 1 GLSA(s) (202004-10), 1 atom(s) (dev-libs/openssl); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-1967
redhat high — https://access.redhat.com/security/cve/CVE-2020-1967
suse high — https://www.suse.com/security/cve/CVE-2020-1967/
ubuntu high CVE-2020-1967 high priority: Ubuntu including 3 source packages (edk2, openssl, openssl1.0), 18 status rows across 6 suites (bionic, eoan, focal, trusty, upstream, xenial): not-affected 9, DNE 5, needs-triage 2, released 2. https://ubuntu.com/security/CVE-2020-1967

Affected software / configurations for CVE-2020-1967

Vendor Product Version Raw CPE
openssl openssl >= 1.1.1d, <= 1.1.1f cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
freebsd freebsd 12.1 cpe:2.3:o:freebsd:freebsd:12.1:-:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
oracle application_server 12.1.3 cpe:2.3:a:oracle:application_server:12.1.3:*:*:*:*:*:*:*
oracle enterprise_manager_base_platform 13.4.0.0 cpe:2.3:a:oracle:enterprise_manager_base_platform:13.4.0.0:*:*:*:*:*:*:*
oracle enterprise_manager_for_storage_management 13.3.0.0 cpe:2.3:a:oracle:enterprise_manager_for_storage_management:13.3.0.0:*:*:*:*:*:*:*
oracle enterprise_manager_for_storage_management 13.4.0.0 cpe:2.3:a:oracle:enterprise_manager_for_storage_management:13.4.0.0:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.4.0 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0:*:*:*:*:*:*:*
oracle http_server 12.2.1.4.0 cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*
oracle jd_edwards_world_security a9.4 cpe:2.3:a:oracle:jd_edwards_world_security:a9.4:*:*:*:*:*:*:*
oracle mysql <= 5.6.48 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql >= 5.7.0, <= 5.7.30 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql >= 8.0.0, <= 8.0.20 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
oracle mysql_connectors <= 8.0.20 cpe:2.3:a:oracle:mysql_connectors:*:*:*:*:*:*:*:*
oracle mysql_enterprise_monitor <= 4.0.12 cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*
oracle mysql_enterprise_monitor >= 8.0.0, <= 8.0.20 cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*
oracle mysql_workbench <= 8.0.21 cpe:2.3:a:oracle:mysql_workbench:*:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.56 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.56:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.57 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.58 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.58:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.59 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.59:*:*:*:*:*:*:*
netapp active_iq_unified_manager >= 7.3 cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:windows:*:*
netapp active_iq_unified_manager >= 9.5 cpe:2.3:a:netapp:active_iq_unified_manager:*:*:*:*:*:vmware_vsphere:*:*
netapp e-series_performance_analyzer — cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:*
netapp oncommand_insight — cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
netapp oncommand_workflow_automation — cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
netapp smi-s_provider — cpe:2.3:a:netapp:smi-s_provider:-:*:*:*:*:*:*:*
netapp snapcenter — cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*
netapp steelstore_cloud_integrated_storage — cpe:2.3:a:netapp:steelstore_cloud_integrated_storage:-:*:*:*:*:*:*:*
broadcom fabric_operating_system — cpe:2.3:o:broadcom:fabric_operating_system:-:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
jdedwards enterpriseone < 9.2.5.0 cpe:2.3:a:jdedwards:enterpriseone:*:*:*:*:*:*:*:*
tenable log_correlation_engine < 6.0.9 cpe:2.3:a:tenable:log_correlation_engine:*:*:*:*:*:*:*:*

References for CVE-2020-1967

URL Tags
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
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