Improper Certificate Validation Affecting stunnel package, versions [,5.57)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.12% (47th percentile)

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  • Snyk IDSNYK-UNMANAGED-STUNNEL-2370292
  • published26 Jan 2022
  • disclosed23 Feb 2021
  • creditUnknown

Introduced: 23 Feb 2021

CVE-2021-20230  (opens in a new tab)
CWE-295  (opens in a new tab)

How to fix?

Upgrade stunnel to version 5.57 or higher.

Overview

Affected versions of this package are vulnerable to Improper Certificate Validation. 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.

References

CVSS Scores

version 3.1