Hello,
Thanks to everyone having answered me earlier, I've managed to set up password policy on the OpenLDAP provided in CentOS 5.5 repositories (current version 2.3.43).
The setup: we have password policy enabled for users accounts in our intranet. After 5 unsuccessful attempts the account is blocked for short duration (30 seconds).
Does that mean that anyone now can keep all the accounts blocked most of the time? Am I right that if anyone enters someone else' incorrect password 5 times (in the given case), they will block the target account (regardless of what IP address the attacker was connecting from)?
Narrower question: do password policy module developers plan to take into account what IPs are used to connect (thus, blocking only access from specific IPs)?
Thanks. All the best, Konstantin
On Tuesday, 1 March 2011 07:23:41 Konstantin Boyandin wrote:
Hello,
Thanks to everyone having answered me earlier, I've managed to set up password policy on the OpenLDAP provided in CentOS 5.5 repositories (current version 2.3.43).
The setup: we have password policy enabled for users accounts in our intranet. After 5 unsuccessful attempts the account is blocked for short duration (30 seconds).
Does that mean that anyone now can keep all the accounts blocked most of the time?
Well, you do the maths.
But, surely you have enough monitoring in place that you would be able to notice a high rate of unsuccessful binds, so that the duration of "most of the time" would not be very long.
Am I right that if anyone enters someone else' incorrect password 5 times (in the given case), they will block the target account (regardless of what IP address the attacker was connecting from)?
Yes. But, where is the line between a DoS and an attempt to break into an account?
In either case, if this *is* only in your intranet, behaviour like this would surely violate your terms of use policy ...
Narrower question: do password policy module developers plan to take into account what IPs are used to connect (thus, blocking only access from specific IPs)?
Maybe you should provide a specific use case, besides "my users violate my terms of use, and I can't do anything about it".
Regards, Buchan
Hello Buchan,
01.03.2011 13:29, Buchan Milne writes:
On Tuesday, 1 March 2011 07:23:41 Konstantin Boyandin wrote:
Hello,
Thanks to everyone having answered me earlier, I've managed to set up password policy on the OpenLDAP provided in CentOS 5.5 repositories (current version 2.3.43).
The setup: we have password policy enabled for users accounts in our intranet. After 5 unsuccessful attempts the account is blocked for short duration (30 seconds).
Does that mean that anyone now can keep all the accounts blocked most of the time?
Well, you do the maths.
But, surely you have enough monitoring in place that you would be able to notice a high rate of unsuccessful binds, so that the duration of "most of the time" would not be very long.
While I am talking of the intranet, I feel I am in control. Logs are monitored and if someone causes repetitive account lockouts, it's easy to detect.
Problems can happen when there is need to open certain services from outside (email, for example).
Am I right that if anyone enters someone else' incorrect password 5 times (in the given case), they will block the target account (regardless of what IP address the attacker was connecting from)?
Yes. But, where is the line between a DoS and an attempt to break into an account?
In either case, if this *is* only in your intranet, behaviour like this would surely violate your terms of use policy ...
Of course.
Narrower question: do password policy module developers plan to take into account what IPs are used to connect (thus, blocking only access from specific IPs)?
Maybe you should provide a specific use case, besides "my users violate my terms of use, and I can't do anything about it".
A typical use case is this. We make users change their passwords regularly, password policy was introduced to further urge to use safer credentials.
Now imagine a person's email being checked regularly from outside the intranet. After the specified attempts the account gets locked. The only option we have in such a case is to firewall the address that sends wrong credentials.
In case the locks are IP-bound, they would only affect those attempting to gain access (regardless of whether those are legitimate or unauthorized attempts).
Thanks. Sincerely, Konstantin
----- "Konstantin Boyandin" temmokan@gmail.com wrote:
Narrower question: do password policy module developers plan to
take
into account what IPs are used to connect (thus, blocking only
access
from specific IPs)?
Maybe you should provide a specific use case, besides "my users
violate my
terms of use, and I can't do anything about it".
A typical use case is this. We make users change their passwords regularly, password policy was introduced to further urge to use safer credentials.
Now imagine a person's email being checked regularly from outside the intranet. After the specified attempts the account gets locked. The only option we have in such a case is to firewall the address that sends wrong credentials.
There are other options. ppolicy is not meant to prevent attacks on accounts, but to try and prevent attacks on accounts being successful. Prevention (or other responses) are only possible if the attacks are detected. If you want attackers to be able to make as many attempts as they like to try and compromise accounts, you would be better off without ppolicy.
In case the locks are IP-bound, they would only affect those attempting to gain access (regardless of whether those are legitimate or unauthorized attempts).
But it opens you up to making it easier for attackers to brute-force your accounts.
However, in your scenario of a user's email account being attacked, to LDAP, the client IP address is that of your mail server, so having IP-specific lockout would not help you.
Regards, Buchan
openldap-technical@openldap.org
-
Buchan Milne -
Konstantin Boyandin