# CVE-2021-20230: stunnel: Stunnel is a wrapper for network connections

CVE-2021-20230 is fixed in 2 products on 1 platform, first by RHSA-2021:0618, released February 22, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-20230
- Priority: High
- CVSS: 7.5 (Important)
- EPSS: 0.0118
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 22, 2021

## Description

Stunnel is a wrapper for network connections. It can be used to tunnel an unencrypted network connection over an encrypted connection (encrypted using SSL or TLS) or to provide an encrypted means of connecting to services that do not natively support encryption.  Security Fix(es):  * stunnel: client certificate not correctly verified when redirect and verifyChain options are used (CVE-2021-20230)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | stunnel RHEL 8 | 0:5.56-5.el8_3 | [RHSA-2021:0618](https://patchblox.com/security/data/fix/linux/rhsa-2021-0618.md) | Feb 22, 2021 |
| Linux | stunnel ol 8 | 0:5.56-5.el8_3 | [ELSA-2021-0618](https://patchblox.com/security/data/fix/linux/elsa-2021-0618.md) | Feb 23, 2021 |
| Linux | stunnel4 Ubuntu 18.04.6 LTS (bionic) | 3:5.44-1ubuntu3+esm1 | [stunnel4 3:5.44-1ubuntu3+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-stunnel4-3-5.44-1ubuntu3-esm1.md) | Feb 23, 2021 |
| Linux | stunnel4 Ubuntu 20.04 LTS (focal) | 3:5.56-1ubuntu0.2 | [stunnel4 3:5.56-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-stunnel4-3-5.56-1ubuntu0.2.md) | Feb 23, 2021 |

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