Red Hat Bugzilla – Bug 101361
RHSA-2003:222-01 breaks active directory authenticated KRB5 PAM
Last modified: 2007-04-18 12:56:26 EDT
Description of problem: application of RHSA-2003:222-01 (upgrade to SSH) seems
to break the use of KRB5 PAM authentication for SSH logins. It is possible to
log in as root but not as a user. The session is immediately terminated by the
Version-Release number of selected component (if applicable): known broken on
RH7.2 and 8.0 as per advisory.
How reproducible: apply patches. set machine to authenticate users using KRB5
with an active directory domain controller as the KRB5 server
Steps to Reproduce:
1. apply patches
2. set machine to authenticate users using KRB5 with an active directory domain
controller as the KRB5 server
3. ssh to machine as user - fails
4. use authconfig to unset KRB5 authentication
5. ssh to machine as user - works
Additional info: rollback to previous version of SSH on affected machines works
Agreed here. Bad patch needs to be rolled back.
Same failures with ssh v1 and ssh v2, with or without X11 forwarding.
/usr/sbin/sshd -D -d -d dies with a segfault.
debug1: userauth-request for user rcgraves service ssh-connection method password
debug1: attempt 2 failures 2
debug2: input_userauth_request: try method password
debug1: Calling cleanup 0x8070d70(0x0)
Possible dupe at bug 101183
I am having the same problem on several machines.
I have not full investigated the security implications of this, but you can
enable "Do not require Kerberos Preauthentication" in your AD accounts to get
There are two other possible workarounds, downgrade openssh to the previous
package, or upgrade the krb5 libraries to the copy on rawhide, though in the
latter case you will probably have to upgrade several other packages as well.
I have another workaround/some more information. I found that the new rpm works
with a Sun krb5 server but not a Windows DC. If I change my krb5.conf to
authenticate against a Sun krb5 server, I can login with ssh. If I use the
Windows DC, ssh fails.
However, I can still login at the console with the Windows krb5 server, and I
can still generate a krb5 ticket (kinit) with the Windows DC. Ditto for the
Sun. It is only ssh that fails with the Windows DC.
This appears to be fixed with the latest update to openssh.
*** This bug has been marked as a duplicate of 101183 ***
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.