VDB
CVE-2021-20230
CVE-2021-20230
PUBLISHED
CVSS 7.5 HIGH
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 1.18% · 67.4th percentile
Risk Scores
CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score
1.18%
67.4th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:20.04:LTS | stunnel4 | 3:5.55-2build1, 3:5.56-1, 0 |
| Ubuntu:Pro:18.04:LTS | stunnel4 | 3:5.44-1ubuntu2, 0, * |
Timeline
- Feb 21, 2021 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 23, 2021 EPSS Score
- Aug 26, 2021 EPSS Score
- Dec 30, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Mar 4, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- May 6, 2022 EPSS Score
- Sep 10, 2022 EPSS Score
- Nov 13, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2021-20230 advisory
- https://github.com/mtrojnar/stunnel/commit/ebad9ddc4efb2635f37174c9d800d06206f1edf9 fix
- https://ubuntu.com/security/notices/USN-6901-1 advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1925226 third-party-advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1177580 third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2021-20230 third-party-advisory