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Unsecured Credentials: Cloud Instance Metadata API

ID Name
T1552.001 Credentials In Files
T1552.002 Credentials in Registry
T1552.003 Bash History
T1552.004 Private Keys
T1552.005 Cloud Instance Metadata API
T1552.006 Group Policy Preferences
T1552.007 Container API

Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.

Most cloud service providers support a Cloud Instance Metadata API which is a service provided to running virtual instances that allows applications to access information about the running virtual instance. Available information generally includes name, security group, and additional metadata including sensitive data such as credentials and UserData scripts that may contain additional secrets. The Instance Metadata API is provided as a convenience to assist in managing applications and is accessible by anyone who can access the instance.[1] A cloud metadata API has been used in at least one high profile compromise.[2]

If adversaries have a presence on the running virtual instance, they may query the Instance Metadata API directly to identify credentials that grant access to additional resources. Additionally, attackers may exploit a Server-Side Request Forgery (SSRF) vulnerability in a public facing web proxy that allows the attacker to gain access to the sensitive information via a request to the Instance Metadata API.[3]

The de facto standard across cloud service providers is to host the Instance Metadata API at http[:]//169.254.169.254.

ID: T1552.005
Sub-technique of:  T1552
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Tactic: Credential Access
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Platforms: IaaS
Contributors: Praetorian
Version: 1.2
Created: 11 February 2020
Last Modified: 31 March 2021
Provided by LAYER 8

Procedure Examples

ID Name Description
S0601 Hildegard

Hildegard has queried the Cloud Instance Metadata API for cloud credentials.[4]
G0139 TeamTNT

TeamTNT has queried the AWS instance metadata service for credentials.[5]

Mitigations

ID Mitigation Description
M1042 Disable or Remove Feature or Program

Disable unnecessary metadata services and restrict or disable insecure versions of metadata services that are in use to prevent adversary access.[6]
M1037 Filter Network Traffic

Limit access to the Instance Metadata API using a host-based firewall such as iptables. A properly configured Web Application Firewall (WAF) may help prevent external adversaries from exploiting Server-side Request Forgery (SSRF) attacks that allow access to the Cloud Instance Metadata API.[3]

Detection

ID Data Source Data Component
DS0002 User Account User Account Authentication

Monitor access to the Instance Metadata API and look for anomalous queries.

It may be possible to detect adversary use of credentials they have obtained such as in Valid Accounts.

References

  1. AWS. (n.d.). Instance Metadata and User Data. Retrieved July 18, 2019.
  2. Krebs, B.. (2019, August 19). What We Can Learn from the Capital One Hack. Retrieved March 25, 2020.
  3. Higashi, Michael. (2018, May 15). Instance Metadata API: A Modern Day Trojan Horse. Retrieved July 16, 2019.
  1. Chen, J. et al. (2021, February 3). Hildegard: New TeamTNT Cryptojacking Malware Targeting Kubernetes. Retrieved April 5, 2021.
  2. Fiser, D. Oliveira, A. (n.d.). Tracking the Activities of TeamTNT A Closer Look at a Cloud-Focused Malicious Actor Group. Retrieved September 22, 2021.
  3. MacCarthaigh, C. (2019, November 19). Add defense in depth against open firewalls, reverse proxies, and SSRF vulnerabilities with enhancements to the EC2 Instance Metadata Service. Retrieved October 14, 2020.