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:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	anon.amish, vcrhonek
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-11 20:16:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
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.

References:
https://www.fetchmail.info/fetchmail-SA-2021-02.txt
http://www.openwall.com/lists/oss-security/2021/08/27/3
https://www.fetchmail.info/security.html

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):

https://access.redhat.com/security/cve/cve-2021-39272