CVE-2020-1967

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 60.8%, top 2% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
7.5
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 53%
CISA-KEV: Not listedEPSS: 53%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.5
EG Score
7.5(medium)
EPSS
98.9%
KEV
Not listed

Published

April 21, 2020

Last Modified

November 21, 2024

References (64)

Affected Packages

(1 across 1 ecosystem)
crates.io(1)
PackageVulnerable rangeFixed inDependents
openssl-src—111.9.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 4× in last 7d / 31× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-11 08:25 UTCEPSS rescore
  3. 2026-07-09 19:07 UTCEPSS rescore
  4. 2026-07-08 15:12 UTCEPSS rescore
  5. 2026-07-05 02:27 UTCEPSS rescore
  6. 2026-07-02 00:01 UTCOSV refresh
  7. 2026-07-01 15:03 UTCEPSS rescore
  8. 2026-06-30 23:20 UTCEPSS rescore
  9. 2026-06-30 23:20 UTCEPSS rescore
  10. 2026-06-28 04:54 UTCEPSS rescore
  11. 2026-06-28 04:54 UTCEPSS rescore
  12. 2026-06-27 03:06 UTCEPSS rescore
  13. 2026-06-25 13:47 UTCEPSS rescore
  14. 2026-06-24 14:03 UTCEPSS rescore
  15. 2026-06-24 14:03 UTCEPSS rescore
  16. 2026-06-23 21:31 UTCEPSS rescore
  17. 2026-06-23 21:31 UTCEPSS rescore
  18. 2026-06-22 14:23 UTCEPSS rescore
  19. 2026-06-22 14:23 UTCEPSS rescore
  20. 2026-06-21 14:54 UTCEPSS rescore
  21. 2026-06-21 14:54 UTCEPSS rescore
  22. 2026-06-21 01:57 UTCEPSS rescore
  23. 2026-06-21 01:57 UTCEPSS rescore
  24. 2026-06-18 17:50 UTCEPSS rescore
  25. 2026-06-17 17:50 UTCEPSS rescore
Show 31 more
  1. 2026-06-16 17:50 UTCEPSS rescore
  2. 2026-06-16 17:50 UTCEPSS rescore
  3. 2026-06-15 17:46 UTCEPSS rescore
  4. 2026-06-14 23:15 UTCEPSS rescore
  5. 2026-06-14 04:13 UTCOSV refresh
  6. 2026-06-12 23:10 UTCEPSS rescore
  7. 2026-06-11 13:58 UTCEPSS rescore
  8. 2026-06-10 22:16 UTCEPSS rescore
  9. 2026-06-10 22:16 UTCEPSS rescore
  10. 2026-06-10 13:20 UTCEPSS rescore
  11. 2026-06-08 14:15 UTCEPSS rescore
  12. 2026-06-08 14:15 UTCEPSS rescore
  13. 2026-06-07 15:23 UTCEPSS rescore
  14. 2026-06-07 15:23 UTCEPSS rescore
  15. 2026-06-06 13:45 UTCEPSS rescore
  16. 2026-06-06 13:45 UTCEPSS rescore
  17. 2026-06-05 22:45 UTCEPSS rescore
  18. 2026-06-05 22:45 UTCEPSS rescore
  19. 2026-06-05 06:08 UTCEPSS rescore
  20. 2026-06-05 06:08 UTCEPSS rescore
  21. 2026-06-02 20:11 UTCEPSS rescore
  22. 2026-06-02 20:11 UTCEPSS rescore
  23. 2026-06-01 13:50 UTCEPSS rescore
  24. 2026-06-01 13:50 UTCEPSS rescore
  25. 2026-05-31 00:15 UTCEPSS rescore
  26. 2026-05-31 00:15 UTCEPSS rescore
  27. 2026-05-29 13:42 UTCEPSS rescore
  28. 2026-05-28 13:43 UTCEPSS rescore
  29. 2026-05-28 13:43 UTCEPSS rescore
  30. 2026-05-27 13:39 UTCEPSS rescore
  31. 2026-05-27 04:32 UTCEG score recompute

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCirsl/CVE-2020-1967
    First seen Apr 28, 2020

    Proof of concept exploit about OpenSSL signature_algorithms_cert DoS flaw (CVE-2020-1967)

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2020-1967?
CVE-2020-1967 is a high vulnerability published on April 21, 2020. Server or client applications that call the SSLcheckchain() 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 "signaturealgorithmscert" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm…
When was CVE-2020-1967 disclosed?
CVE-2020-1967 was first published in the National Vulnerability Database on April 21, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-1967 actively exploited?
CVE-2020-1967 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-1967?
CVE-2020-1967 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2020-1967?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-1967, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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