Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Bug 1026921

Summary: useless similarity check
Product: Red Hat Enterprise Linux 7 Reporter: Karel Volný <kvolny>
Component: libpwqualityAssignee: Tomas Mraz <tmraz>
Status: CLOSED WONTFIX QA Contact: BaseOS QE Security Team <qe-baseos-security>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0   
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-11-05 16:48:58 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Karel Volný 2013-11-05 16:23:16 UTC
Description of problem:
I've just wanted to correct wrongly entered password (due to different keyboard layout) but was disallowed to. This makes no sense, as it can be easily workarounded by changing to something completely different at first, then changing to whatever you need, it just annoys the user.

Version-Release number of selected component (if applicable):
passwd-0.79-1.el7

How reproducible:
always

Steps to Reproduce:
1. run passwd (as ordinary user)
2. try to change the password to nearly the same as before just with one character different

Actual results:
you get BAD PASSWORD error and cannot use the new password

Expected results:
the password gets changed

Additional info:

Comment 2 Miloslav Trmač 2013-11-05 16:38:41 UTC
This check happens in *pwquality (... and is configured in system-auth, which Tomáš owns as well.)

Reassigning for him to consider.

FWIW, the workaround you propose can be, and is in some deployments, prevented by setting up a minimal password validity, and potentially remembering more past passwords.

Comment 3 Tomas Mraz 2013-11-05 16:48:38 UTC
You can also set up minimal number of days before you're allowed to change your password again.

The similarity check was there for a very long time and I don't think we should remove it. Basically all the checks in libpwquality/cracklib can be sometimes annoying but with this attitude we could drop pam_pwquality from the system-auth altoghether.