--- Begin Message ---
Hello Sascha,
From the defensics logs, it can be confirmed that Authentication Bypass has
happened, but again we are checking with Defensics team whether it is false
positive or not?
Also, about the manual verification of the issue, we are checking with
Defensics team, how to reproduce manually.
Does this mean that any one of the passwords that are associated with a user on
the device allows access regardless of the username?
Does authentication also work if an existing user name is used, but with a
different user’s password?
What is the “malformed value”? The password was said to be correct…
If @Nitesh Srivastava<mailto:[email protected]> can provide other
username/passwords we can verify the same.
The malformed value in the username fields can be anything (like hexadecimal
20).
Regards,
Ravi Chaitanya.
Device Security Assurance Centre
For any DSAC enquiries, please send an E-mail to
[email protected]<mailto:[email protected]>
To get news and update on DSAC, please subscribe to DSAC mailing
list<http://www.abb.com/global/gad/GAD01626.nsf/0/60AE9D386FE86E1DC12582140043809E?OpenDocument>.
From: Sascha Stoeter
Sent: Friday, March 22, 2019 8:01 PM
To: Srikant Sana <[email protected]>; Jocelyn Lau
<[email protected]>; V-Ravi-Chaitanya Chebolu
<[email protected]>; Anjana Rajan <[email protected]>;
Joe Doetzl <[email protected]>
Cc: Manish Singh <[email protected]>; Brahmaji Naidu
<[email protected]>; Aneta Jaworska <[email protected]>; Scott
Pate <[email protected]>; Mattias Gustin <[email protected]>;
Nitesh Srivastava <[email protected]>; Hadeli Hadeli
<[email protected]>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
In addition, has anyone manually confirmed the Defensics finding or is it a
false positive?
Sascha
From: Sascha Stoeter
Sent: Friday, 22 March 2019 14:33
To: Srikant Sana <[email protected]<mailto:[email protected]>>;
Jocelyn Lau <[email protected]<mailto:[email protected]>>;
V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>; Joe
Doetzl <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Brahmaji Naidu <[email protected]<mailto:[email protected]>>;
Aneta Jaworska <[email protected]<mailto:[email protected]>>;
Scott Pate <[email protected]<mailto:[email protected]>>; Mattias
Gustin <[email protected]<mailto:[email protected]>>; Nitesh
Srivastava <[email protected]<mailto:[email protected]>>;
Hadeli Hadeli ([email protected]<mailto:[email protected]>)
<[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hi all
Is the Defensics finding the only issue holding back the release?
Ravi:
> But on Defensics the issue reported as Authentication Bypass is different.
> Here, the Defensics sends valid Username with no password, for which PCU400
> responds with Authorization failure,
That’s as expected.
> then Defensics sends with invalid username with valid password (malformed
> value) and determines that Authentication Bypass was possible.
Does this mean that any one of the passwords that are associated with a user on
the device allows access regardless of the username?
Does authentication also work if an existing user name is used, but with a
different user’s password?
What is the “malformed value”? The password was said to be correct…
Srikant:
Is the issue described above only allowing access to the PCUCAG module or to a
wider set of functionality?
> In the current test scenario if authentication fails there is no possibility
> to send a command to PCUCAG ,hence restricting the access for external
> application to make any attempts to fail.
I’m not sure what this is supposed to say. The issue here is that
authentication succeeds when it’s supposed to fail.
> The alternate solution suggested below is to restrict the access to system
> to only local system where in operator has to log locally to access PCUCAG
> functionality , no external access to the system till the issue is resolved.
That’s the option that would prevent further release delays caused by the
finding.
Cheers,
Sascha
From: Srikant Sana
Sent: Friday, 22 March 2019 10:33
To: Jocelyn Lau <[email protected]<mailto:[email protected]>>;
V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Brahmaji Naidu <[email protected]<mailto:[email protected]>>;
Aneta Jaworska <[email protected]<mailto:[email protected]>>;
Scott Pate <[email protected]<mailto:[email protected]>>; Mattias
Gustin <[email protected]<mailto:[email protected]>>; Nitesh
Srivastava <[email protected]<mailto:[email protected]>>;
Sascha Stoeter <[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hi Jocelyn ,
PCU400 and PCUCAG details
PCU400 is front end which basically acts communication server between NM SCADA
server and field RTUs/devices.
The module in testing here is PCUCAG , which provide an interface to operator
to enable/disable the communication details.
The data coming into and going out of PCU are written into log (trace) files
and at the same time display the details on Putty (SSH) session through which
the user is connected to the PCU application.
There is list of predefined commands to enable/disable logging , any other
message coming to PCUCAG will be discarded if that does not meet standard
syntax.
So PCUCAG core functionality is to inform the Protocol drivers in the system
to enable/disable logs in PCU and write the details to log/flat files ,
primarily to support in trouble shooting of the system in commission stage or
later based on the need.
In the current test scenario if authentication fails there is no possibility to
send a command to PCUCAG ,hence restricting the access for external application
to make any attempts to fail.
Even if this or any other application in PCU fails there is inbuilt mechanism
to restart that.
The alternate solution suggested below is to restrict the access to system to
only local system where in operator has to log locally to access PCUCAG
functionality , no external access to the system till the issue is resolved.
Please let me know if any further details are required on this.
Regards
Srikant
From: Jocelyn Lau
Sent: Friday, March 22, 2019 12:14 PM
To: Srikant Sana <[email protected]<mailto:[email protected]>>;
V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Brahmaji Naidu <[email protected]<mailto:[email protected]>>;
Aneta Jaworska <[email protected]<mailto:[email protected]>>;
Scott Pate <[email protected]<mailto:[email protected]>>; Mattias
Gustin <[email protected]<mailto:[email protected]>>; Nitesh
Srivastava <[email protected]<mailto:[email protected]>>;
Sascha Stoeter <[email protected]<mailto:[email protected]>>
Subject: Re: compilation issue found in libssh-0.7.6 on VS2017
[+Sascha]
Hello Srikant…
We cannot change the severity without more information from the vendor. It
sounds like this ticket has been opened now and we can try to escalate this.
(@Rchaitanya Chebolu<mailto:[email protected]> / @Anjana
Rajan<mailto:[email protected]>: can you help with this?)
In parallel while we work with the test vendor, let’s start the conversation
with Sascha regarding a possible exception. If you can provide more
information to him, I have a meeting with him tomorrow afternoon to sync up and
we can discuss this topic in our agenda.
Regards,
Jocelyn
From: Srikant Sana <[email protected]<mailto:[email protected]>>
Date: Thursday, March 21, 2019 at 11:17 PM
To: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>,
Jocelyn Lau <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>,
Anjana Rajan <[email protected]<mailto:[email protected]>>,
Brahmaji Naidu <[email protected]<mailto:[email protected]>>,
Aneta Jaworska <[email protected]<mailto:[email protected]>>,
Scott Pate <[email protected]<mailto:[email protected]>>, Mattias
Gustin <[email protected]<mailto:[email protected]>>, Nitesh
Srivastava <[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hi Jocelyn & Ravi ,
Thank you for the support and inputs on analysis of the reported issue.
As it seems to be an issue specific to tool can we have an exception or
recategorization of issue currently it reported as critical issue, as it may
take time to resolve from Vendor side as well.
Alternatively we can restrict the access of application to Local Host only
where in if required the Operator will connect to PCU system using remote
desktop. Currently an operator can connect to the system using Putty (SSH)
from a remote system.
We have a G5 planned by end of this month so please let us know how we can
proceed further on this .
Regards
Srikant
From: V-Ravi-Chaitanya Chebolu
Sent: Friday, March 22, 2019 9:09 AM
To: Jocelyn Lau <[email protected]<mailto:[email protected]>>; Nitesh
Srivastava <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>; Srikant
Sana <[email protected]<mailto:[email protected]>>; Brahmaji Naidu
<[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hello Jocelyn,
Thanks for your mail. I have already raised a support query with Synopsis and
awaiting their response. I will update you once I get any update from them.
Regards,
Ravi Chaitanya.
Device Security Assurance Centre
For any DSAC enquiries, please send an E-mail to
[email protected]<mailto:[email protected]>
To get news and update on DSAC, please subscribe to DSAC mailing
list<http://www.abb.com/global/gad/GAD01626.nsf/0/60AE9D386FE86E1DC12582140043809E?OpenDocument>.
From: Jocelyn Lau
Sent: Thursday, March 21, 2019 8:02 PM
To: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>;
Nitesh Srivastava
<[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>; Srikant
Sana <[email protected]<mailto:[email protected]>>; Brahmaji Naidu
<[email protected]<mailto:[email protected]>>
Subject: Re: compilation issue found in libssh-0.7.6 on VS2017
Hello Ravi..
Thank you for the detailed description/background for this issue. I would
recommend that we first open a support ticket with Synopsys to ask them about
this discrepancy. Based on their analysis, we can then discuss the question of
the severity of this issue.
Thanks,
Jocelyn
From: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>
Date: Thursday, March 21, 2019 at 5:01 AM
To: Jocelyn Lau <[email protected]<mailto:[email protected]>>, Nitesh
Srivastava <[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>,
Anjana Rajan <[email protected]<mailto:[email protected]>>, Srikant
Sana <[email protected]<mailto:[email protected]>>, Brahmaji Naidu
<[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hello Jocelyn,
In PCU400, there is a high severity issue called “Authentication Bypass”
vulnerability.
Earlier, PCU400 was using libSSH version less than 0.7.6 which had
Authentication Bypass vulnerability which was reported by both Nessus and
Defensics.
So, PCU400 team has updated the libSSH package to 0.7.7, which has mitigation
for Authentication Bypass.
Now when Nessus was run (with libssh 0.7.6 or 0.7.7) this Authentication Bypass
was not reported. As Authentiction Bypass was observed for lower versions than
0.7.6, which is occurred by, a user could just skip the authentication process
and have his client send the SSH2_MSG_USERAUTH_SUCCESS and bypass all checks
instead of sending SSH2_MSG_USERAUTH_REQUEST.
But on Defensics the issue reported as Authentication Bypass is different.
Here, the Defensics sends valid Username with no password, for which PCU400
responds with Authorization failure, then Defensics sends with invalid username
with valid password (malformed value) and determines that Authentication Bypass
was possible.
So, the issue is not fixed as per Defensics.
But the BU says that this service is not critical. Can you please let them
know, if it is possible to change the severity level from high to medium.
Regards,
Ravi Chaitanya.
Device Security Assurance Centre
For any DSAC enquiries, please send an E-mail to
[email protected]<mailto:[email protected]>
To get news and update on DSAC, please subscribe to DSAC mailing
list<http://www.abb.com/global/gad/GAD01626.nsf/0/60AE9D386FE86E1DC12582140043809E?OpenDocument>.
From: Nitesh Srivastava
Sent: Thursday, March 21, 2019 2:19 AM
To: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>; Srikant
Sana <[email protected]<mailto:[email protected]>>; Brahmaji Naidu
<[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hi Ravi,
We have tested our PCU400 with all the latest versions of libssh(0.7.6 & 0.8.7)
and resolved Authentication Bypass issue successfully.
For the issue reported in defensics, Authentication Bypass was successful by
entering invalid string in username field: I must say this situation will
never occur in PCU400 system. The reason is, in PCU400 system pcucag run as
background process and used to collect the logs for PCU400 bug investigation.
To connect with pcucag, process in PCU400 is done through localhost via any
libssh based application (Putty) and this processing is done after connecting
via Remote desktop connection (Encrypted method) at customer place by using
authorized PSO/Customer person.
Also in PCU400 system, pcucag is not the critical process and the connections
are discarding for invalid username and password. I’ll suggest please consider
this as an exceptional issue.
Please suggest and let me know about your concern.
Regards,
Nitesh
—
Nitesh Srivastava
Network Control Solutions
ABB Ability & Innovation Centre
3rd Floor, Bhoruka Tech Park
Mahadevpura Main Road,
560048, Bengaluru (India)
Mobile: +91 9379416369
abb.com
From: V-Ravi-Chaitanya Chebolu
Sent: Monday, March 11, 2019 10:03 AM
To: Srikant Sana <[email protected]<mailto:[email protected]>>;
Nitesh Srivastava
<[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>;
Anjana Rajan <[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hello Srikanth,
We are still awaiting response from Defensics.
The issues seems to be different in a way that the one fixed by libSSH versin
0.7.6 is Authentication Bypass which is occurred by, a user could just skip the
authentication process and have his client send the SSH2_MSG_USERAUTH_SUCCESS
and bypass all checks instead of sending SSH2_MSG_USERAUTH_REQUEST. This issue
is not reported now.
But the one reported in defensics is different, in the Authorization Service
Request Message message Defensics is appending invalid string in username field
and it reported that Autentication Bypass was successful.
Regards,
Ravi Chaitanya.
Device Security Assurance Centre
For any DSAC enquiries, please send an E-mail to
[email protected]<mailto:[email protected]>
To get news and update on DSAC, please subscribe to DSAC mailing
list<http://www.abb.com/global/gad/GAD01626.nsf/0/60AE9D386FE86E1DC12582140043809E?OpenDocument>.
From: Srikant Sana
Sent: Monday, March 11, 2019 8:59 AM
To: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>;
Nitesh Srivastava
<[email protected]<mailto:[email protected]>>
Cc: Manish Singh <[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hi Ravi ,
Is the downgraded version of Libssh also showing same issues , If so when we
can expect a response from the Defensics or is there way to take exception for
this?
Based on your input , the Gate meeting has to be planned .
Regards
Srikant
From: V-Ravi-Chaitanya Chebolu
Sent: Thursday, March 07, 2019 5:34 PM
To: Nitesh Srivastava
<[email protected]<mailto:[email protected]>>
Cc: Srikant Sana <[email protected]<mailto:[email protected]>>;
Manish Singh <[email protected]<mailto:[email protected]>>
Subject: RE: compilation issue found in libssh-0.7.6 on VS2017
Hello Nitesh,
This issue is reported by Defensics and we have raised a support case with
them, once we get a response from them, we will let you know.
Regards,
Ravi Chaitanya.
Device Security Assurance Centre
For any DSAC enquiries, please send an E-mail to
[email protected]<mailto:[email protected]>
To get news and update on DSAC, please subscribe to DSAC mailing
list<http://www.abb.com/global/gad/GAD01626.nsf/0/60AE9D386FE86E1DC12582140043809E?OpenDocument>.
From: Nitesh Srivastava
Sent: Thursday, March 07, 2019 5:20 PM
To: V-Ravi-Chaitanya Chebolu
<[email protected]<mailto:[email protected]>>
Cc: Srikant Sana <[email protected]<mailto:[email protected]>>
Subject: FW: compilation issue found in libssh-0.7.6 on VS2017
Hi Ravi,
We have checked with libssh.org and as per them “Authentication bypass
vulnerability" is fixed in version 0.7.7.
Below is the response, Please have a look.
Regards,
Nitesh
-----Original Message-----
From: Andreas Schneider <[email protected]<mailto:[email protected]>>
Sent: Thursday, March 07, 2019 4:24 PM
To: [email protected]<mailto:[email protected]>
Cc: Nitesh Srivastava
<[email protected]<mailto:[email protected]>>
Subject: Re: compilation issue found in libssh-0.7.6 on VS2017
CAUTION: This email originated from outside of the organization. Do not click
links or open attachments unless you recognize the sender and know the content
is safe.
On Wednesday, March 6, 2019 7:05:22 PM CET Nitesh Srivastava wrote:
> Hi Andreas,
>
> Thanks for reply. I used the libssh-0.7.7 version and its compiled for me.
>
> But during my Product device security testing through synopsis tool
> its failed for "Authentication bypass vulnerability" in version 0.7.7.
I would argue that this tool is broken. We have unit tests which proof that it
is fixed ;-)
--
Andreas Schneider
[email protected]<mailto:[email protected]>
GPG-ID: 8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D
--- End Message ---