Bug 1912460 (CVE-2020-25275)

Summary:	CVE-2020-25275 dovecot: Denial of service via mail MIME parsing
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	anon.amish, bennie.joubert, janfrode, mhlavink
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	dovecot 2.3.13	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-05-18 20:38:04 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:	1912461, 1914019, 1914020
Bug Blocks:	1912462

Description Pedro Sampaio 2021-01-04 14:43:51 UTC

A flaw was found in dovecot before version 2.3.13. Mail parsing crashed when the 10 000th MIME part was message/rfc822 (or if parent was multipart/digest). This happened due to earlier MIME parsing changes for CVE-2020-12100.

References:

https://www.openwall.com/lists/oss-security/2021/01/04/3
https://dovecot.org/pipermail/dovecot-news/2021-January/000448.html

Comment 1 Pedro Sampaio 2021-01-04 14:44:19 UTC

Created dovecot tracking bugs for this issue:

Affects: fedora-all [bug 1912461]

Comment 2 Todd Cullum 2021-01-08 00:51:53 UTC

Upstream commits:
https://github.com/dovecot/core/commit/266e54b7b8c34c9a58dd60a2e53c5ca7d1deae19
https://github.com/dovecot/core/commit/fb97a1cddbda4019e327fa736972a1c7433fedaa

Comment 4 Todd Cullum 2021-01-08 01:04:04 UTC

Mitigation:

A potential mitigation is configuring the mail transfer agent to not accept messages with more than 10,000 MIME parts.

Comment 5 Todd Cullum 2021-01-08 01:15:44 UTC

External References:

https://dovecot.org/pipermail/dovecot-news/2021-January/000448.html

Comment 6 errata-xmlrpc 2021-05-18 15:51:53 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1887 https://access.redhat.com/errata/RHSA-2021:1887

Comment 7 Product Security DevOps Team 2021-05-18 20:38:04 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-2020-25275