Bug 2105070 (CVE-2022-30550) - CVE-2022-30550 dovecot: Privilege escalation when similar master and non-master passdbs are used
Summary: CVE-2022-30550 dovecot: Privilege escalation when similar master and non-mast...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2022-30550
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2106227 2106228 2106229 2106231 2106232
Blocks: 2105072
TreeView+ depends on / blocked
 
Reported: 2022-07-07 20:13 UTC by Sage McTaggart
Modified: 2022-12-04 19:33 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2022-12-04 19:33:23 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2022:7623 0 None None None 2022-11-08 09:51:21 UTC
Red Hat Product Errata RHSA-2022:8208 0 None None None 2022-11-15 10:36:49 UTC

Description Sage McTaggart 2022-07-07 20:13:55 UTC
Affected product: Dovecot IMAP Server 
Internal reference: DOV-5320
Vulnerability type: Improper Access Control (CWE-284) 
Vulnerable version: 2.2
Vulnerable component: submission 
Report confidence: Confirmed 
Solution status: Fixed in main
Researcher credits: Julian Brook (julezman)
Vendor notification: 2022-05-06 
CVE reference: CVE-2022-30550
CVSS: 6.8 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N) 

Vulnerability Details: 
When two passdb configuration entries exist in Dovecot configuration, which have the same driver and args settings, the incorrect username_filter and mechanism settings can be applied to passdb definitions. These incorrectly applied settings can lead to an unintended security configuration and can permit privilege escalation with certain configurations involving master user authentication.

Dovecot documentation does not advise against the use of passdb definitions which have the same driver and args settings. One such configuration would be where an administrator wishes to use the same pam configuration or passwd file for both normal and master users but use the username_filter setting to restrict which of the users is able to be a master user.

Risk: 
If same passwd file or PAM is used for both normal and master users, it is possible for attacker to become master user.

Workaround:
Always authenticate master users from different source than regular users, e.g. using a separate passwd file. Alternatively, you can use global ACLs to ensure that only legimate master users have priviledged access.

Fix:
This has been fixed in main branch. See https://github.com/dovecot/core/compare/7bad6a24%5E..a1022072.patch

Comment 4 TEJ RATHI 2022-07-12 06:22:57 UTC
Created dovecot tracking bugs for this issue:

Affects: fedora-all [bug 2106228]


Created dovecot-fts-xapian tracking bugs for this issue:

Affects: epel-8 [bug 2106227]
Affects: fedora-all [bug 2106229]

Comment 8 errata-xmlrpc 2022-11-08 09:51:19 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:7623 https://access.redhat.com/errata/RHSA-2022:7623

Comment 9 errata-xmlrpc 2022-11-15 10:36:47 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2022:8208 https://access.redhat.com/errata/RHSA-2022:8208

Comment 10 Product Security DevOps Team 2022-12-04 19:33:22 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-2022-30550


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