CVE-2020-1967 high CVSS 7.5

Vulnerability in Openssl Http Server (CVE-2020-1967)

Summary

Vulnerability in Openssl Http Server (CVE-2020-1967). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

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).

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2020-1967 has been found in Openssl Http Server.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Openssl Http Server CVE-2020-1967" on the vendor's site.

CVE-2020-1967 (Openssl Http Server) — CWE-476 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Affected: 1.1.1d - 1.1.1f
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-476) exists in Openssl Http Server.

📍 Affected scope

Affected versions of Openssl Http Server: 1.1.1d - 1.1.1f.

🔥 Severity

Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory. (If a vulnerable version 1.1.1d - 1.1.1f is in production, plan an immediate maintenance window.)

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで Openssl Http Server を使っているサービスとバージョンを洗い出す。
2
Match against affected range verify
```
Confirm if version satisfies `1.1.1d - 1.1.1f`
```
Step 1 で見つかったバージョンが影響範囲 1.1.1d - 1.1.1f に該当するか照合。本番で稼働中ならインシデント扱い。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

crates.io openssl-src

[{"type":"SEMVER","events":[{"introduced":"111.6.0"},{"fixed":"111.9.0"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Alpine Linux ALPINE-CVE-2020-1967 openssl Fixed in: 1.1.1g-r0
Debian DEBIAN-CVE-2020-1967 openssl Fixed in: 1.1.1g-1