Bug 1351593 (CVE-2016-5404)

Summary: CVE-2016-5404 ipa: Insufficient privileges check in certificate revocation
Product: [Other] Security Response Reporter: Andrej Nemec <anemec>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anemec, cbuissar, ftweedal, jcholast, mkosek, pvoborni, rcritten, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
An insufficient permission check issue was found in the way IPA server treats certificate revocation requests. An attacker logged in with the 'retrieve certificate' permission enabled could use this flaw to revoke certificates, possibly triggering a denial of service attack.
 Story Points: ---
Clone Of: Environment:
Last Closed: 2016-09-01 14:11:59 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: 1366979, 1366980, 1366981, 1366982, 1367883    
Bug Blocks: 1351595    
Attachments:
Description Flags
Patch for ipa-4.4
none
Patch for ipa-4.3
none
Patch for ipa-4.2
none
Patch for ipa-4.1
none
Patch for ipa-3.0 AND ipa-2.1 none

Description Andrej Nemec 2016-06-30 11:54:16 UTC 
Summary: a user with 'retrieve certificate' permission can revoke
any certificate.  The 'revoke certificate' permission is not
required.

Detail: the 'cert_revoke' command does check for the 'revoke
certificate' permission, however, if an access error is raised, it
then invokes the 'cert_show' command.  The rational was to re-use a
"self-service" check that is part of the 'cert_show' command,
however, it is sufficient that 'cert_show' execute successfully for
'cert_revoke' to recover from the access error and continue.
Therefore, anyone with 'retrieve certificate' permission can revoke
*any* certificate.

Impact: anyone with 'retrieve certificate' permission can cause
various kinds of DoS by revoking any cert they want.

Scope: Every supported versions of RHEL with IDM are affected.
Comment 1 Andrej Nemec 2016-06-30 11:54:21 UTC 
Acknowledgments:

Name: Fraser Tweedale (Red Hat)
Comment 16 Cedric Buissart 2016-08-17 17:25:01 UTC 
Created freeipa tracking bugs for this issue:

Affects: fedora-all [bug 1367883]
Comment 17 Fedora Update System 2016-08-29 18:54:00 UTC 
freeipa-4.3.2-2.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.
Comment 18 errata-xmlrpc 2016-09-01 13:58:44 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2016:1797 https://rhn.redhat.com/errata/RHSA-2016-1797.html