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CVE-2021-20230 Detail

Description

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.


Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  7.5 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://bugzilla.redhat.com/show_bug.cgi?id=1925226 Issue Tracking  Third Party Advisory 
https://github.com/mtrojnar/stunnel/commit/ebad9ddc4efb2635f37174c9d800d06206f1edf9 Patch  Third Party Advisory 
https://security.gentoo.org/glsa/202105-02 Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-295 Improper Certificate Validation Provider acceptance level Red Hat, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-20230
NVD Published Date:
02/23/2021
NVD Last Modified:
06/01/2022
Source:
Red Hat, Inc.