VDB

CVE-2021-20230

CVE-2021-20230 PUBLISHED

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.

EPSS 0.21% · 43.4th percentile

Risk Scores

EPSS Score
0.21%
43.4th percentile

Affected Products

VendorProductVersions
Ubuntu:20.04:LTSstunnel43:5.55-2build1, 3:5.56-1, 0
Ubuntu:Pro:18.04:LTSstunnel43:5.44-1ubuntu2, 0, *

Timeline

  • Feb 21, 2021 CVE Published
  • Apr 14, 2021 EPSS Score
  • Jun 23, 2021 EPSS Score
  • Aug 24, 2021 EPSS Score
  • Oct 26, 2021 EPSS Score
  • Jan 6, 2022 EPSS Score
  • Feb 4, 2022 EPSS Score
  • Feb 28, 2022 EPSS Score
  • Apr 1, 2022 EPSS Score
  • May 1, 2022 EPSS Score
  • Jul 3, 2022 EPSS Score
  • Sep 4, 2022 EPSS Score
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