CVE-2021-20230

mediumPriorität · verfolgen · 30EPSS 0.012 · 68. PerzentilDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.18% (68th) EPSS
CVSS 5 · medium
Is it mine?
97 products
Prüfe deine Angriffsfläche
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · bewertet 2026-10-27

A flaw was found in stunnel before 5.57, where it improperly validates client certificates when it is configured to use both redirect and verifyChain options. This flaw allows an attacker with a certificate signed by a Certificate Authority, which is not the one accepted by the stunnel server, to access the tunneled service instead of being redirected to the address specified in the redirect option. The highest threat from this vulnerability is to confidentiality.

01

Behebungen

Hersteller-Fix, Mitigation oder Workaround, wie von den Quellen veröffentlicht.

Ein Hersteller-Fix ist verfügbar.

  • Behobenstunnel-0:5.56-5.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-0:5.56-5.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-0:5.56-5.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-0:5.56-5.el8_3.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-0:5.56-5.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debuginfo-0:5.56-5.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debuginfo-0:5.56-5.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debuginfo-0:5.56-5.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debuginfo-0:5.56-5.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debugsource-0:5.56-5.el8_3.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debugsource-0:5.56-5.el8_3.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debugsource-0:5.56-5.el8_3.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-debugsource-0:5.56-5.el8_3.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0618
  • Behobenstunnel-0:5.48-6.el8_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-0:5.48-6.el8_2.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-0:5.48-6.el8_2.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-0:5.48-6.el8_2.src as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-0:5.48-6.el8_2.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debuginfo-0:5.48-6.el8_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debuginfo-0:5.48-6.el8_2.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debuginfo-0:5.48-6.el8_2.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debuginfo-0:5.48-6.el8_2.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debugsource-0:5.48-6.el8_2.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debugsource-0:5.48-6.el8_2.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debugsource-0:5.48-6.el8_2.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-debugsource-0:5.48-6.el8_2.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.2)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0619
  • Behobenstunnel-0:5.48-6.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-0:5.48-6.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-0:5.48-6.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-0:5.48-6.el8_1.src as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-0:5.48-6.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debuginfo-0:5.48-6.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debuginfo-0:5.48-6.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debuginfo-0:5.48-6.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debuginfo-0:5.48-6.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debugsource-0:5.48-6.el8_1.aarch64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debugsource-0:5.48-6.el8_1.ppc64le as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debugsource-0:5.48-6.el8_1.s390x as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
  • Behobenstunnel-debugsource-0:5.48-6.el8_1.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS (v. 8.1)redhat_csaf

    For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258

    https://access.redhat.com/errata/RHSA-2021:0620
02

cvss

Technischer Schweregrad, 0–10. Eine Zeile je Quelle.

7.5
010

Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen⚠ Quellen uneinig · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USAusnutzbarkeit 10 · Auswirkung 2.9
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USAusnutzbarkeit 3.9 · Auswirkung 3.6
v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · Red Hat Product Security US
03

schwächen

Die CWE-Schwächeklassen, zu denen dies gehört.

CWE-295USCWE-295USCWE-295US
04

betroffene Produkte (97)

Betroffene Produkte und Versionsbereiche.

20 von 97 angezeigt
05

Advisories (4)

Hersteller- und Ökosystem-Meldungen dazu.

  • RHSA-2021:0618Red Hat Security Advisory: stunnel security update2021-02-22csaf · redhat_csafUS

    An update for stunnel is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2021:0619Red Hat Security Advisory: stunnel security update2021-02-22csaf · redhat_csafUS

    An update for stunnel is now available for Red Hat Enterprise Linux 8.2 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2021:0620Red Hat Security Advisory: stunnel security update2021-02-22csaf · redhat_csafUS

    An update for stunnel is now available for Red Hat Enterprise Linux 8.1 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • WID-SEC-W-2024-1674Red Hat Enterprise Linux: Schwachstelle ermöglicht Umgehen von SicherheitsvorkehrungenDeutsch2021-02-21csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

06

auch bekannt als (4)

Weitere Namen und Kennungen dieser Entität.

07

quellen

Welche Quellen diesen Datensatz belegen und wann.

cnnvdenisa_euvdfstec_bducert_bundredhat_csafNVDCVE.orgMITRE
veröffentlicht 2021-02-23geändert 2026-06-17
08

Referenzen (18)

Externe Belege — Patches, Meldungen, Analysen.

scry

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