CVE-2021-20230
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.
Risk Information
Base Score
7.5
MODERATE
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score
Exploitation Probability
0.209
Associated Vulnerability
| Vulnerability | OS Platform |
|---|---|
| Vulnerabilities CVE-2021-20230 are affected in stunnel 5.54 | Windows |
| (RHSA-2021:0618) stunnel security update stunnel-5.56-5.el8_3.x86_64.rpm | Linux |
| (RHSA-2021:0618) stunnel security update stunnel-debugsource-5.56-5.el8_3.x86_64.rpm | Linux |
| Stunnel update (ELSA-2021-0618) stunnel-5.56-5.el8_3.x86_64.rpm | Linux |
| stunnel update (TU-CESAS-0018) stunnel-5.71-1.el8.x86_64.rpm | Linux |
| stunnel update (TU-CESAS-0018) stunnel-5.71-2.el8.x86_64.rpm | Linux |
| cups update (TU-CESAS-0018) cups-filters-1.20.0-32.el8.x86_64.rpm | Linux |
| python3 update (TU-CESAS-0018) python3-requests-2.20.0-4.el8.noarch.rpm | Linux |
| cups update (TU-CESAS-0018) cups-filters-libs-1.20.0-32.el8.i686.rpm | Linux |
| cups update (TU-CESAS-0018) cups-filters-libs-1.20.0-32.el8.x86_64.rpm | Linux |
| samba update (TU-CESAS-0018) samba-vfs-iouring-4.18.6-100.el9.x86_64.rpm | Linux |
| (RHSA-2021:0618)Important: security update stunnel-debuginfo-5.56-5.el8_3.x86_64.rpm | Linux |
| stunnel security update (RLSA-2021:0618) stunnel-5.56-5.el8_3.x86_64.rpm | Linux |
| Universal SSL tunnel for network daemons (USN-6901-1) stunnel4_5.56-1ubuntu0.2_amd64.deb | Linux |
| Universal SSL tunnel for network daemons (USN-6901-1) stunnel4_5.56-1ubuntu0.2_i386.deb | Linux |
Patch Details
Click to see the patches provided by ManageEngine for this CVE
| Patch ID | Patch Description |
|---|---|
| PATCH-348313 | stunnel (5.75) |
References
https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234