All,
I apologize if this has been covered already. But this was just brought up by our cybersecurity team. They plan to disable "deprecated protocols". By that, they mean simple LDAP binding to AD's LDAP port. Because of passing content in clear text.
They flagged our Linux AD connections (using sssd), which are using SASL binding. The usual sssd stuff:
- adcli join, - /etc/krb5.keytab file, - ldap_sasl_authid = <machine account>
to AD's LDAP port and the LDAP GC port.
Flagging those connections is a mistake; these connections are encrypted.
https://www.pkisolutions.com/reminder-ldap-signing-requirements-in-march-202...
But cybersecurity is asking -- are the question "are these connections signed?". I don't know the answer to that. If not, is there a simple parameter that will allow sssd to sign these connections. Or is "signing" a SASL binding a characteristic of the MS-Specific SASL binding (MS-SPNG)?
BTW, we use a couple of AD integration clients for Linux. sssd can satisfy 95% of the use cases, but there's a couple of use cases that sssd can't do. For that, we have to use the older (commercial) product. That older commercial product does *not* have any support to run SASL binding over LDAPS.
So why I realize that I could technically have sssd run its SASL bindings over LDAPS -- that other client can't. So I'm not really investigating SASL bindings over LDAPS.
Spike
On Wed, Sep 2, 2020 at 1:46 PM Spike White spikewhitetx@gmail.com wrote:
I apologize if this has been covered already. But this was just brought up by our cybersecurity team. They plan to disable "deprecated protocols". By that, they mean simple LDAP binding to AD's LDAP port. Because of passing content in clear text.
This was covered already, yes. Here’s a summary:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
For the full discussion, search the list archives for these threads:
Subject: [SSSD-users] Re: sssd 1.16.4. ADV190023. Subject: [SSSD-users] SSSD and the forthcoming Active Directory LDAPocalypse
But cybersecurity is asking -- are the question "are these connections signed?". I don't know the answer to that.
They are signed, yes, despite the warning that is logged on the DC. You can verify this with a packet trace. See:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
Using GSS-SPNEGO instead of GSSAPI will silence the warning, but older systems (e.g. RHEL6) don’t have GSS-SPNEGO.
Thank you.
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
We have a MS consultant, but they're not sssd-knowledgeable.
Spike
On Wed, Sep 2, 2020 at 2:02 PM James Ralston ralston@pobox.com wrote:
On Wed, Sep 2, 2020 at 1:46 PM Spike White spikewhitetx@gmail.com wrote:
I apologize if this has been covered already. But this was just brought up by our cybersecurity team. They plan to disable "deprecated protocols". By that, they mean simple LDAP binding to AD's LDAP port. Because of passing content in clear text.
This was covered already, yes. Here’s a summary:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
For the full discussion, search the list archives for these threads:
Subject: [SSSD-users] Re: sssd 1.16.4. ADV190023. Subject: [SSSD-users] SSSD and the forthcoming Active Directory LDAPocalypse
But cybersecurity is asking -- are the question "are these connections signed?". I don't know the answer to that.
They are signed, yes, despite the warning that is logged on the DC. You can verify this with a packet trace. See:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
Using GSS-SPNEGO instead of GSSAPI will silence the warning, but older systems (e.g. RHEL6) don’t have GSS-SPNEGO. _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
I believe it will still connect to the LDAP and GC ports, just the protocol changes. To my knowledge going with the AD provider might help but you're using LDAP for a reason instead I assume. Thinking about it though LDAP and CLDAP calls will still connect to those ports.
-- lawrence
On Wed, Sep 2, 2020 at 3:17 PM Spike White spikewhitetx@gmail.com wrote:
Thank you.
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
We have a MS consultant, but they're not sssd-knowledgeable.
Spike
On Wed, Sep 2, 2020 at 2:02 PM James Ralston ralston@pobox.com wrote:
On Wed, Sep 2, 2020 at 1:46 PM Spike White spikewhitetx@gmail.com wrote:
I apologize if this has been covered already. But this was just brought up by our cybersecurity team. They plan to disable "deprecated protocols". By that, they mean simple LDAP binding to AD's LDAP port. Because of passing content in clear text.
This was covered already, yes. Here’s a summary:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
For the full discussion, search the list archives for these threads:
Subject: [SSSD-users] Re: sssd 1.16.4. ADV190023. Subject: [SSSD-users] SSSD and the forthcoming Active Directory LDAPocalypse
But cybersecurity is asking -- are the question "are these connections signed?". I don't know the answer to that.
They are signed, yes, despite the warning that is logged on the DC. You can verify this with a packet trace. See:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
Using GSS-SPNEGO instead of GSSAPI will silence the warning, but older systems (e.g. RHEL6) don’t have GSS-SPNEGO. _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
On Wed, Sep 2, 2020 at 3:17 PM Spike White spikewhitetx@gmail.com wrote:
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
Unfortunately, there is not. A DC will log this event:
The following client performed a SASL (Negotiate/Kerberos/NTLM/Digest) LDAP bind without requesting signing (integrity verification), or performed a simple bind over a clear text (non-SSL/TLS-encrypted) LDAP connection.
…for both of these use cases:
1. An LDAP client uses GSSAPI (instead of GSS-SPNEGO), over a signed and sealed connection. No passwords are transmitted in clear text.
2. An LDAP client performs a simple bind over clear text (without sealing), which passes the bind password on the wire in clear text.
If the DCs are configured as per Microsoft’s recommendations to secure LDAP traffic, use case #2 will break. But use case #1 will not. (Others in the big long thread I referenced in my previous message verified this.)
At least to my knowledge, no one has figured out a way to sift through these events in the event log and determine which ones (if any) were generated by LDAP clients performing simple binds over clear text (which is undesirable) versus which ones were generated by LDAP clients using GSSAPI (instead of GSS-SPNEGO) over a sealed connection.
Alas, Microsoft really should have used two different event types to distinguish these cases.
James,
Really appreciate this detailed answer. Our on-site MS consultant will be back next week, we'll have a big conversation next week.
BTW, you reminded me. Our AD team has a few AD DCs configured for this proposed "future state" configuration -- which will break the use case #2 above. I tested our Linux sssd clients against it, as well as our older (commercial product) clients. Both ran fine.
Lawrence, we *are* using the AD provider. internally, the AD provider is doing GSSAPI-based SASL LDAP binding by default. We have a mix of RHEL6,7 and 8 boxes.
Spike
On Wed, Sep 2, 2020 at 3:55 PM James Ralston ralston@pobox.com wrote:
On Wed, Sep 2, 2020 at 3:17 PM Spike White spikewhitetx@gmail.com wrote:
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
Unfortunately, there is not. A DC will log this event:
The following client performed a SASL (Negotiate/Kerberos/NTLM/Digest) LDAP bind without requesting signing (integrity verification), or performed a simple bind over a clear text (non-SSL/TLS-encrypted) LDAP connection.…for both of these use cases:
An LDAP client uses GSSAPI (instead of GSS-SPNEGO), over a signed and sealed connection. No passwords are transmitted in clear text.
An LDAP client performs a simple bind over clear text (without sealing), which passes the bind password on the wire in clear text.
If the DCs are configured as per Microsoft’s recommendations to secure LDAP traffic, use case #2 will break. But use case #1 will not. (Others in the big long thread I referenced in my previous message verified this.)
At least to my knowledge, no one has figured out a way to sift through these events in the event log and determine which ones (if any) were generated by LDAP clients performing simple binds over clear text (which is undesirable) versus which ones were generated by LDAP clients using GSSAPI (instead of GSS-SPNEGO) over a sealed connection.
Alas, Microsoft really should have used two different event types to distinguish these cases. _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
On Wed, Sep 02, 2020 at 05:12:45PM -0500, Spike White wrote:
James,
Really appreciate this detailed answer. Our on-site MS consultant will be back next week, we'll have a big conversation next week.
BTW, you reminded me. Our AD team has a few AD DCs configured for this proposed "future state" configuration -- which will break the use case #2 above. I tested our Linux sssd clients against it, as well as our older (commercial product) clients. Both ran fine.
Lawrence, we *are* using the AD provider. internally, the AD provider is doing GSSAPI-based SASL LDAP binding by default. We have a mix of RHEL6,7 and 8 boxes.
Hi,
James is right on spot. About the logged event when using GSSAPI my colleague Thorsten also asked Microsoft in the Comments to https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/ldap...
There is also https://access.redhat.com/articles/4661861 which is updated as soon as we have more information to share on this topic. One of the latest updates here is about LDAPS and channel binding. Here work on cyrus-sasl, openldap and MIT Kerberos was needed to make the initial support all those components had work together as expected.
HTH
bye, Sumit
Spike
On Wed, Sep 2, 2020 at 3:55 PM James Ralston ralston@pobox.com wrote:
On Wed, Sep 2, 2020 at 3:17 PM Spike White spikewhitetx@gmail.com wrote:
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
Unfortunately, there is not. A DC will log this event:
The following client performed a SASL (Negotiate/Kerberos/NTLM/Digest) LDAP bind without requesting signing (integrity verification), or performed a simple bind over a clear text (non-SSL/TLS-encrypted) LDAP connection.…for both of these use cases:
An LDAP client uses GSSAPI (instead of GSS-SPNEGO), over a signed and sealed connection. No passwords are transmitted in clear text.
An LDAP client performs a simple bind over clear text (without sealing), which passes the bind password on the wire in clear text.
If the DCs are configured as per Microsoft’s recommendations to secure LDAP traffic, use case #2 will break. But use case #1 will not. (Others in the big long thread I referenced in my previous message verified this.)
At least to my knowledge, no one has figured out a way to sift through these events in the event log and determine which ones (if any) were generated by LDAP clients performing simple binds over clear text (which is undesirable) versus which ones were generated by LDAP clients using GSSAPI (instead of GSS-SPNEGO) over a sealed connection.
Alas, Microsoft really should have used two different event types to distinguish these cases. _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
All,
This is exactly what our cybersecurity team is reporting on. Log event ID 2289 showing up in the AD domain controller logs for Linux clients (using sssd). Upon further research, Microsoft has just released a patch to fix their mis-reporting:
https://support.microsoft.com/en-us/help/4559003/windows-10-update-kb4559003
July 21, 2020—KB4559003 (OS Build 17763.1369). Fix for Windows 10 and Windows Server
Here's the exact bugfix (from the above URL):
- Addresses an issue that incorrectly reports Lightweight Directory Access Protocol (LDAP) sessions as unsecure sessions in Event ID 2889. This occurs when the LDAP session is authenticated and sealed with a Simple Authentication and Security Layer (SASL) method.
Spike
On Thu, Sep 3, 2020 at 1:46 AM Sumit Bose sbose@redhat.com wrote:
On Wed, Sep 02, 2020 at 05:12:45PM -0500, Spike White wrote:
James,
Really appreciate this detailed answer. Our on-site MS consultant will be back next week, we'll have a big conversation next week.
BTW, you reminded me. Our AD team has a few AD DCs configured for this proposed "future state" configuration -- which will break the use case #2 above. I tested our Linux sssd clients against it, as well as our older (commercial product) clients. Both ran fine.
Lawrence, we *are* using the AD provider. internally, the AD provider is doing GSSAPI-based SASL LDAP binding by default. We have a mix of RHEL6,7 and 8 boxes.
Hi,
James is right on spot. About the logged event when using GSSAPI my colleague Thorsten also asked Microsoft in the Comments to
https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/ldap...
There is also https://access.redhat.com/articles/4661861 which is updated as soon as we have more information to share on this topic. One of the latest updates here is about LDAPS and channel binding. Here work on cyrus-sasl, openldap and MIT Kerberos was needed to make the initial support all those components had work together as expected.
HTH
bye, Sumit
Spike
On Wed, Sep 2, 2020 at 3:55 PM James Ralston ralston@pobox.com wrote:
On Wed, Sep 2, 2020 at 3:17 PM Spike White spikewhitetx@gmail.com
wrote:
What cybersecurity is reporting off of is a particular event number on its AD controllers. which is showing a connection to a LDAP port.
Is there another (better) event that it should be looking for instead? I.e., it should be flagging a simple binding only to an LDAP port.
Unfortunately, there is not. A DC will log this event:
The following client performed a SASL (Negotiate/Kerberos/NTLM/Digest) LDAP bind without requesting signing (integrity verification), or performed a simple bind over a clear text (non-SSL/TLS-encrypted) LDAP connection.…for both of these use cases:
An LDAP client uses GSSAPI (instead of GSS-SPNEGO), over a signed and sealed connection. No passwords are transmitted in clear text.
An LDAP client performs a simple bind over clear text (without sealing), which passes the bind password on the wire in clear text.
If the DCs are configured as per Microsoft’s recommendations to secure LDAP traffic, use case #2 will break. But use case #1 will not. (Others in the big long thread I referenced in my previous message verified this.)
At least to my knowledge, no one has figured out a way to sift through these events in the event log and determine which ones (if any) were generated by LDAP clients performing simple binds over clear text (which is undesirable) versus which ones were generated by LDAP clients using GSSAPI (instead of GSS-SPNEGO) over a sealed connection.
Alas, Microsoft really should have used two different event types to distinguish these cases. _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct:
https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives:
https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o... _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.o...
sssd-users@lists.fedorahosted.org
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James Ralston -
Lawrence Kearney -
Spike White -
Sumit Bose