- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gentoo Linux Security Advisory                           GLSA 202105-02
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                            https://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Severity: Low
     Title: stunnel: Improper certificate validation
      Date: May 26, 2021
      Bugs: #772146
        ID: 202105-02

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis
=======
Stunnel was not properly verifying TLS certificates, possibly allowing
an integrity/confidentiality compromise.

Background
=========
The stunnel program is designed to work as an SSL/TLS encryption
wrapper between a client and a local or remote server.

Affected packages
================
     -------------------------------------------------------------------
      Package              /     Vulnerable     /            Unaffected
     -------------------------------------------------------------------
   1  net-misc/stunnel              < 5.58                     >= 5.58

Description
==========
It was discovered that stunnel did not correctly verified the client
certificate when options "redirect" and "verifyChain" are used.

Impact
=====
A remote attacker could send a specially crafted certificate, possibly
resulting in a breach of integrity or confidentiality.

Workaround
=========
There is no known workaround at this time.

Resolution
=========
All stunnel users should upgrade to the latest version:

   # emerge --sync
   # emerge --ask --oneshot --verbose ">=net-misc/stunnel-5.58"

References
=========
[ 1 ] CVE-2021-20230
       https://nvd.nist.gov/vuln/detail/CVE-2021-20230

Availability
===========
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  https://security.gentoo.org/glsa/202105-02

Concerns?
========
Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
======
Copyright 2021 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5/