vulnerability
Debian: CVE-2021-20230: stunnel4 -- security update
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:P/I:N/A:N) | Feb 23, 2021 | Jul 30, 2024 | Aug 15, 2025 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:P/I:N/A:N)
Published
Feb 23, 2021
Added
Jul 30, 2024
Modified
Aug 15, 2025
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.
Solution
debian-upgrade-stunnel4
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