Bug 1533964 – sudo skips PAM account module in case NOPASSWD is used in sudoers

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Bug 1533964 - sudo skips PAM account module in case NOPASSWD is used in sudoers

Summary:	sudo skips PAM account module in case NOPASSWD is used in sudoers

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	sudo (Show other bugs)
Sub Component:
Version:	7.4
Hardware:	Unspecified Unspecified

Priority	medium Severity medium
Target Milestone:	rc
Target Release:	---
Assigned To:	Daniel Kopeček
QA Contact:	Patrik Kis
Docs Contact:	Mirek Jahoda

URL:
Whiteboard:
Keywords:	FutureFeature, Patch, Triaged

Depends On:	1547974
Blocks:
	Show dependency tree / graph

Reported:	2018-01-12 11:35 EST by Thorsten Scherf
Modified:	2018-10-30 07:09 EDT (History)
CC List:	5 users (show)

See Also:
Fixed In Version:	sudo-1.8.23-1.el7
Doc Type:	Enhancement
Doc Text:	sudo now runs PAM stack even when no authentication is required With this update, the sudo utility runs Pluggable Authentication Module (PAM) account management modules even when the "NOPASSWD" option is configured in the policy. This enables checking for restrictions imposed by PAM modules outside of the authentication phase. As a result, PAM modules, such as `pam_time`, now work properly in the described scenario.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2018-10-30 07:09:01 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
proposed patch (17.91 KB, patch) 2018-01-17 03:31 EST, Daniel Kopeček	no flags	Details \| Diff
upstream fix of a regression related to NOPASSWD PAM stack handling (7.02 KB, patch) 2018-09-24 10:01 EDT, Daniel Kopeček	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Knowledge Base (Solution)	3320531	None	None	None	2018-01-15 04:35 EST
Red Hat Product Errata	RHEA-2018:3199	None	None	None	2018-10-30 07:09 EDT

Groups: None (edit)

Description Thorsten Scherf 2018-01-12 11:35:02 EST

Description of problem:
sudo skips the PAM account phase and therefore also skips the pam_time module which results in failed time based account restriction.  

sudo should use 'pam_acct_mgmt()' in case no authentication is required. The function is fully independent of 'pam_authenticate()'.

http://www.linux-pam.org/Linux-PAM-html/adg-interface-by-app-expected.html#adg-pam_acct_mgmt

Version-Release number of selected component (if applicable):
all versions of sudo are affected.

How reproducible:

/etc/sudoers:
foobar	 ALL=(ALL)	NOPASSWD: ALL

/etc/pam.d/sudo:
account required pam_time.so

/etc/security/time.conf:
sudo;*;*;!Al0000-24000

sudo still works for the 'foobar' user. Expectation is that sudo is failing.

Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:

Comment 3 Daniel Kopeček 2018-01-17 03:31 EST

Created attachment 1382271 [details]
proposed patch

Comment 12 Daniel Kopeček 2018-09-24 10:01 EDT

Created attachment 1486438 [details]
upstream fix of a regression related to NOPASSWD PAM stack handling

Comment 15 errata-xmlrpc 2018-10-30 07:09:01 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2018:3199

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