Bug 1999190 (CVE-2021-39272)

Summary: CVE-2021-39272 fetchmail: STARTTLS session encryption bypassing
Product: [Other] Security Response Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anon.amish, vcrhonek
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Clone Of: Environment:
Last Closed: 2022-05-11 20:16:47 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1999191, 1999275, 1999276    
Bug Blocks: 1999192    

Description Guilherme de Almeida Suckevicz 2021-08-30 16:46:57 UTC
Fetchmail before 6.4.22 fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and PREAUTH.


Comment 1 Guilherme de Almeida Suckevicz 2021-08-30 16:47:12 UTC
Created fetchmail tracking bugs for this issue:

Affects: fedora-all [bug 1999191]

Comment 3 Garrett Tucker 2021-08-30 19:06:47 UTC
This specific flaw is caused by a myriad of factors that result in the possibility of communications being sent in clear text. Due to how IMAP and fetchmail work, it was possible for fetchmail to start communications in clear text and then try to upgrade the communication to an encrypted communication (STARTTLS protocol). However, IMAP in "Pre Auth" mode does not allow for the communications to be started via STARTTLS. Thus if a user used IMAP, the server used Pre Auth, TLS was forced and no ssl mode was configured, the communications would be sent entirely in clear text. This has been solved in Fetchmail 6.4.22 or above.

Comment 5 errata-xmlrpc 2022-05-10 14:33:16 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1964 https://access.redhat.com/errata/RHSA-2022:1964

Comment 6 Product Security DevOps Team 2022-05-11 20:16:45 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):