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CVE-2020-1971 medium CVSS 5.9

Vulnerability in Openssl Http Server (CVE-2020-1971)

Summary

Vulnerability in Openssl Http Server (CVE-2020-1971). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

The X.509 GeneralName type is a generic type for representing different types of names. One of those name types is known as EDIPartyName. OpenSSL provides a function GENERAL_NAME_cmp which compares different instances of a GENERAL_NAME to see if they are equal or not. This function behaves incorrectly when both GENERAL_NAMEs contain an EDIPARTYNAME. A NULL pointer dereference and a crash may occur leading to a possible denial of service attack. OpenSSL itself uses the GENERAL_NAME_cmp function for two purposes: 1) Comparing CRL distribution point names between an available CRL and a CRL distribution point embedded in an X509 certificate 2) When verifying that a timestamp response token signer matches the timestamp authority name (exposed via the API functions TS_RESP_verify_response and TS_RESP_verify_token) If an attacker can control both items being compared then that attacker could trigger a crash. For example if the attacker can trick a client or server into checking a malicious certificate against a malicious CRL then this may occur. Note that some applications automatically download CRLs based on a URL embedded in a certificate. This checking happens prior to the signatures on the certificate and CRL being verified. OpenSSL's s_server, s_client and verify tools have support for the "-crl_download" option which implements automatic CRL downloading and this attack has been demonstrated to work against those tools. Note that an unrelated bug means that affected versions of…

Source: NIST National Vulnerability Database NVD

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-2020-1971 has been found in Openssl Http Server.
Risk of unauthorized operations or information disclosure. CVSS score: 5.9/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Openssl Http Server CVE-2020-1971" on the vendor's site.

CVE-2020-1971 (Openssl Http Server) — CWE-476 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Affected: 1.1.1 - 1.1.1h
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: 1.1.1 - 1.1.1h.

🔥 Severity

Severity: Medium (CVSS 5.9/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory. (If a vulnerable version 1.1.1 - 1.1.1h 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. 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. 2
    Match against affected range verify 
    Confirm if version satisfies `1.1.1 - 1.1.1h`

    Step 1 で見つかったバージョンが影響範囲 1.1.1 - 1.1.1h 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. 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。

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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