adalanche v20211005 releases: Active Directory ACL Visualizer

adalanche – Active Directory ACL Visualizer and Explorer

Active Directory security is notoriously difficult. Small organizations generally have no idea what they’re doing, and way too many people are just added to Domain Admins. In large organizations you have a huge number of people with different needs, and they are delegated access to varying degrees of power in the AD. At some point in time, someone makes a mistake, and that can cost you dearly.

User Interface

When launched, you get to see who can pwn “Domain Admins” and “Enterprise Admins”. Query targets are marked with RED. If you get a lot of objects on this one, congrats, you’re running a pwnshop.

The below examples loaded from the included domain beyond.local, which is a synthetic domain, that has been heavy-handedly been messed up using BadBlood. You can try the same analysis with: adalanche -domain beyond.local analyze

Your browser should pop up with:

No really exciting results on this synthetic AD. Yes, some users are Domain Admins and Administrators. But let’s expand the search a bit.

Analysis Methods

Press the “Analysis Methods” tab on the bottom portion of the page, and you get this:

(more methods has been added since this screenshot)

The tool can look for many scenarios but defaults to fairly simple ones that can get you control of an object. As this yielded nothing, let’s try to expand with all methods enabled. Checking the missing boxes, we submit another query.

LDAP query pop-out

When you press the “LDAP Query” tab on the bottom portion of the page, and you get the search interface:

You enter a query for things you want to search for. Optionally you can also add a secondary exclude query, separating the include and exclude queries with a comma.

• The “Queries” button is just for inspiration, with some predefined queries to get you going.
• The “Safe”/”Force” button allows you to run requests that return more than 1000 objects (potentially crashing your browser tab).
• “Max Depth” can limit results by not going further from a target than this depth.

Analyze:

• Normal searches for other objects that can pwn the selection in your LDAP query (i.e. who can reach these objects)
• Reverse searches for objects that you LDAP query targets can pwn (i.e. what can these objects reach)

I enabled “Force” as I was warned that the analysis would return more than 1000 objects, and pressed “Analyze / Normal”.

Whoa – that’s a lot. But can all these objects then suddenly do a system takeover? No, not necessarily, this depends on the analysis methods used. We enabled the CanDelete*, CanCreate*, and InheritsSecurity methods.

Let’s investigate what’s going on here – right-click on one of your targets, and choose “Set as target”.

Then right-click on someone else, and choose “Route to target”.

Then you’ll get a route, which shows the best way to the target.

So here the problem is just a matter of groups being nested members of other groups, but at the very end, you see that someone set the DELETE_CHILD flag on the parent container, yielding the right to delete (or potentially move) the target. That does look wrong, doesn’t it?

If you examine the “Domain Users” object, you will see that it doesn’t have the InheritsSecurity flag, so you can’t really pwn it by moving it around.

So try it out on your own data – see what your user can pwn by searching for (&(objectCategory=Person)(Name=YOURLOGIN)) and do a Reverse search. Maybe you’ll just end up with the groups that you are a member of, maybe you have access to more than you think …

Remember, you might get too many results. Limit the selection of targets with (&(attribute=something)(_limit=10)) to just get 10 random targets (see LDAP queries below)

Operational theory

adalanche works a bit differently than other tools, as it dumps everything it can from an Active Directory server, which it then saves to a highly compressed binary cache file for later use. This dump can be done by any unprivileged user unless the Active Directory has been hardened to prevent this (almost no one does this).

The analysis phase is done on a cache file, so you do not have to be connected to the systems when doing analysis. This way you can explore different scenarios, and ask questions not easily answered otherwise.

Analysis / Visualization

The tool works as an interactive map in your browser and defaults to a ldap search query that shows you how to become “Domain Admin” or “Enterprise Admin” (i.e. member of said group or takeover of an account which is either a direct or indirect member of these groups.

LDAP queries

The tool has its own LDAP query parser and makes it easy to search for other objects to take over, by using a familiar search language.

The queries support:

• case insensitive matching for all attribute names
• checking whether an attribute exists using asterisk syntax (member=*)
• case insensitive matching for string values using equality (=)
• integer comparison using <, <=, > and >= operators
• glob search using equality if search value includes ? or *
• case sensitive regexp search using equality if search value is enclosed in forward slashes: (name=/^Sir.*Mix.*lot$/ (can be made case insensitive with /(?i)pattern/ flags, see https://github.com/google/re2/wiki/Syntax)
• extensible match: 1.2.840.113556.1.4.803 (you can also use :and:) LDAP_MATCHING_RULE_BIT_AND
• extensible match: 1.2.840.113556.1.4.804 (you can also use :or:) LDAP_MATCHING_RULE_BIT_OR
• extensible match: 1.2.840.113556.1.4.1941 (you can also use :dnchain:) LDAP_MATCHING_RULE_IN_CHAIN
• custom extensible match: count – returns the number of attribute values (member:count:>20 gives groups with more members than 20)
• custom extensible match: length – matches on length of attribute values (name:length:>20 gives you objects with long names)
• custom extensible match: since – parses the attribute as a timestamp and your value as a duration – pwdLastSet:since:<-6Y5M4D3h2m1s (pawLastSet is less than the time 6 years, 5 months, 4 days, 3 hours, 2 minutes, and 1 second ago – or just pass an integer that represents seconds directly)
• synthetic attribute: _limit (_limit=10) returns true on the first 10 hits, false on the rest giving you a max output of 10 items
• synthetic attribute: _random100 (_random100<10) allows you to return a random percentage of results (&(objectclass=Person)(_random100<1)) gives you 1% of users
• synthetic attribute: _canpwn – allows you to select objects based on what they can pwn directly (&(objectclass=Group)(_canpwn=ResetPassword)) gives you all groups that are assigned the reset password right
• synthetic attribute: _pwnable – allows you to select objects based on how they can be pwned directly (&(objectclass=Person)(_pwnable=ResetPassword)) gives you all users that can have their password reset

Install