CAPEC の説明
Through the exploitation of how service accounts leverage Kerberos authentication with Service Principal Names (SPNs), the adversary obtains and subsequently cracks the hashed credentials of a service account target to exploit its privileges. The Kerberos authentication protocol centers around a ticketing system which is used to request/grant access to services and to then access the requested services. As an authenticated user, the adversary may request Active Directory and obtain a service ticket with portions encrypted via RC4 with the private key of the authenticated account. By extracting the local ticket and saving it disk, the adversary can brute force the hashed value to reveal the target account credentials.
CAPEC の情報
実行フロー
1) Explore
Scan for user accounts with set SPN values
技法
- These can be found via Powershell or LDAP queries, as well as enumerating startup name accounts and other means.
2) Explore
Request service tickets
技法
- Using user account's SPN value, request other service tickets from Active Directory
3) Experiment
Extract ticket and save to disk
技法
- Certain tools like Mimikatz can extract local tickets and save them to memory/disk.
4) Exploit
Crack the encrypted ticket to harvest plain text credentials
技法
- Leverage a brute force application/script on the hashed value offline until cracked. The shorter the password, the easier it is to crack.
前提条件
The adversary requires access as an authenticated user on the system. This attack pattern relates to elevating privileges.The adversary requires use of a third-party credential harvesting tool (e.g., Mimikatz).
The adversary requires a brute force tool.
必要なスキル
(Level : Medium)緩和策
Monitor system and domain logs for abnormal access.Employ a robust password policy for service accounts. Passwords should be of adequate length and complexity, and they should expire after a period of time.
Employ the principle of least privilege: limit service accounts privileges to what is required for functionality and no more.
Enable AES Kerberos encryption (or another stronger encryption algorithm), rather than RC4, where possible.
関連する弱点
| 弱点名 | |
|---|---|
CWE-522 |
Insufficiently Protected Credentials The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval. |
CWE-308 |
Use of Single-factor Authentication The product uses an authentication algorithm that uses a single factor (e.g., a password) in a security context that should require more than one factor. |
CWE-309 |
Use of Password System for Primary Authentication The use of password systems as the primary means of authentication may be subject to several flaws or shortcomings, each reducing the effectiveness of the mechanism. |
CWE-294 |
Authentication Bypass by Capture-replay A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). |
CWE-263 |
Password Aging with Long Expiration The product supports password aging, but the expiration period is too long. |
CWE-262 |
Not Using Password Aging The product does not have a mechanism in place for managing password aging. |
CWE-521 |
Weak Password Requirements The product does not require that users should have strong passwords. |
参考文献
REF-559
Extracting Service Account Passwords with KerberoastingJeff Warren.
https://blog.stealthbits.com/extracting-service-account-passwords-with-kerberoasting/
REF-585
Kerberoasting Without Mimikatzhttps://www.harmj0y.net/blog/powershell/kerberoasting-without-mimikatz/
REF-586
Invoke-Kerberoasthttps://powersploit.readthedocs.io/en/latest/Recon/Invoke-Kerberoast/
登録情報
| 名前 | 組織 | 日付 | リリース日 |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation |
変更履歴
| 名前 | 組織 | 日付 | コメント |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation | Updated @Status, Example_Instances, References, Related_Attack_Patterns, Related_Weaknesses, Taxonomy_Mappings | |
| CAPEC Content Team | The MITRE Corporation | Updated Execution_Flow |
