Why isn't this XSS working?PHP: if charset mismatches (htmlentities UTF-8) viewed by client as ISO-8859-1 (or vice versa)How is this XSS attack working?Why doesn't this XSS attack work?XSS - Bypass this RegExpWhy do ID attributes need stricter validation?XSS via JSON: Why does a web application not sanitize either its incoming params hash or its outgoing JSON values of malicious tags like Script?Why isn't this code running?Why does this XSS challenge require %0A to work?BeEF XSS - internal workingWhy this XSS payload doesn't work?
Can I use my Chinese passport to enter China after I acquired another citizenship?
How can I get through very long and very dry, but also very useful technical documents when learning a new tool?
Is exact Kanji stroke length important?
HashMap containsKey() returns false although hashCode() and equals() are true
Modify casing of marked letters
Have I saved too much for retirement so far?
Implement the Thanos sorting algorithm
Can criminal fraud exist without damages?
Are there any comparative studies done between Ashtavakra Gita and Buddhim?
Displaying the order of the columns of a table
Teaching indefinite integrals that require special-casing
Using parameter substitution on a Bash array
Why did Kant, Hegel, and Adorno leave some words and phrases in the Greek alphabet?
Will it be accepted, if there is no ''Main Character" stereotype?
What's the purpose of "true" in bash "if sudo true; then"
How to verify if g is a generator for p?
How can a jailer prevent the Forge Cleric's Artisan's Blessing from being used?
Can somebody explain Brexit in a few child-proof sentences?
Is there a problem with hiding "forgot password" until it's needed?
voltage of sounds of mp3files
Is there a good way to store credentials outside of a password manager?
Tiptoe or tiphoof? Adjusting words to better fit fantasy races
Opposite of a diet
Is there an Impartial Brexit Deal comparison site?
Why isn't this XSS working?
PHP: if charset mismatches (htmlentities UTF-8) viewed by client as ISO-8859-1 (or vice versa)How is this XSS attack working?Why doesn't this XSS attack work?XSS - Bypass this RegExpWhy do ID attributes need stricter validation?XSS via JSON: Why does a web application not sanitize either its incoming params hash or its outgoing JSON values of malicious tags like Script?Why isn't this code running?Why does this XSS challenge require %0A to work?BeEF XSS - internal workingWhy this XSS payload doesn't work?
I'm learning DOM XSS and I have this code :
<html>
<body>
Select your language:
<select>
<script>
document.write("<OPTION value=1>"+document.location.href.substring(document.location.href.indexOf("default=")+8)+"</OPTION>");
document.write("<OPTION value=2>English</OPTION>");
</script>
</select>
</body>
</html>
but I don't understand why this payload doesn't trigger any XSS :
t.html?default=test</option><img src=x onerror=alert(1)/>
It looks like the symbols are encoded and I don't understand why...
I took the script from https://www.owasp.org/index.php/DOM_Based_XSS so I guess it's vulnerable but I don't know how to exploit it...
xss
edited yesterday
Alex Probert
3231215
asked yesterday
NeolexNeolex
10219
add a comment |
I'm learning DOM XSS and I have this code :
<html>
<body>
Select your language:
<select>
<script>
document.write("<OPTION value=1>"+document.location.href.substring(document.location.href.indexOf("default=")+8)+"</OPTION>");
document.write("<OPTION value=2>English</OPTION>");
</script>
</select>
</body>
</html>
but I don't understand why this payload doesn't trigger any XSS :
t.html?default=test</option><img src=x onerror=alert(1)/>
It looks like the symbols are encoded and I don't understand why...
I took the script from https://www.owasp.org/index.php/DOM_Based_XSS so I guess it's vulnerable but I don't know how to exploit it...
xss
edited yesterday
Alex Probert
3231215
asked yesterday
NeolexNeolex
10219
add a comment |
I'm learning DOM XSS and I have this code :
<html>
<body>
Select your language:
<select>
<script>
document.write("<OPTION value=1>"+document.location.href.substring(document.location.href.indexOf("default=")+8)+"</OPTION>");
document.write("<OPTION value=2>English</OPTION>");
</script>
</select>
</body>
</html>
but I don't understand why this payload doesn't trigger any XSS :
t.html?default=test</option><img src=x onerror=alert(1)/>
It looks like the symbols are encoded and I don't understand why...
I took the script from https://www.owasp.org/index.php/DOM_Based_XSS so I guess it's vulnerable but I don't know how to exploit it...
xss
edited yesterday
Alex Probert
3231215
asked yesterday
NeolexNeolex
10219
I'm learning DOM XSS and I have this code :
<html>
<body>
Select your language:
<select>
<script>
document.write("<OPTION value=1>"+document.location.href.substring(document.location.href.indexOf("default=")+8)+"</OPTION>");
document.write("<OPTION value=2>English</OPTION>");
</script>
</select>
</body>
</html>
but I don't understand why this payload doesn't trigger any XSS :
t.html?default=test</option><img src=x onerror=alert(1)/>
It looks like the symbols are encoded and I don't understand why...
I took the script from https://www.owasp.org/index.php/DOM_Based_XSS so I guess it's vulnerable but I don't know how to exploit it...
xss
xss
edited yesterday
Alex Probert
3231215
asked yesterday
NeolexNeolex
10219
edited yesterday
Alex Probert
3231215
asked yesterday
NeolexNeolex
10219
edited yesterday
Alex Probert
3231215
edited yesterday
Alex Probert
3231215
edited yesterday
Alex Probert
3231215
3231215
asked yesterday
NeolexNeolex
10219
asked yesterday
NeolexNeolex
10219
asked yesterday
NeolexNeolex
10219
10219
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
It doesn't work because the payload is URL-encoded.
If you navigate to
https://example.com/?foo=<>"
you will see the literal characters <>" in your URL bar, but the browser has actually requested
https://example.com/?foo=%3C%3E%22
. That is, your browser always URL-encodes some characters in the query string, including quotes and angle brackets.
So, if you access location.href via JS, the payload in your example will be returned as
test%3C/option%3E%3Cimg%20src=x%20onerror=alert(1)/%3E
. This does not produce any HTML tags unless you URL-decode it first.
Note: As far as I know, all modern browsers now behave that way, but historically, some implementations have implicitly URL-decoded values for the location interface. In these browsers, your attack would have worked.
answered yesterday
ArminiusArminius
37.8k13123120
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
add a comment |
Your Answer
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "162"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsecurity.stackexchange.com%2fquestions%2f206018%2fwhy-isnt-this-xss-working%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
It doesn't work because the payload is URL-encoded.
If you navigate to
https://example.com/?foo=<>"
you will see the literal characters <>" in your URL bar, but the browser has actually requested
https://example.com/?foo=%3C%3E%22
. That is, your browser always URL-encodes some characters in the query string, including quotes and angle brackets.
So, if you access location.href via JS, the payload in your example will be returned as
test%3C/option%3E%3Cimg%20src=x%20onerror=alert(1)/%3E
. This does not produce any HTML tags unless you URL-decode it first.
Note: As far as I know, all modern browsers now behave that way, but historically, some implementations have implicitly URL-decoded values for the location interface. In these browsers, your attack would have worked.
answered yesterday
ArminiusArminius
37.8k13123120
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
add a comment |
It doesn't work because the payload is URL-encoded.
If you navigate to
https://example.com/?foo=<>"
you will see the literal characters <>" in your URL bar, but the browser has actually requested
https://example.com/?foo=%3C%3E%22
. That is, your browser always URL-encodes some characters in the query string, including quotes and angle brackets.
So, if you access location.href via JS, the payload in your example will be returned as
test%3C/option%3E%3Cimg%20src=x%20onerror=alert(1)/%3E
. This does not produce any HTML tags unless you URL-decode it first.
Note: As far as I know, all modern browsers now behave that way, but historically, some implementations have implicitly URL-decoded values for the location interface. In these browsers, your attack would have worked.
answered yesterday
ArminiusArminius
37.8k13123120
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
add a comment |
It doesn't work because the payload is URL-encoded.
If you navigate to
https://example.com/?foo=<>"
you will see the literal characters <>" in your URL bar, but the browser has actually requested
https://example.com/?foo=%3C%3E%22
. That is, your browser always URL-encodes some characters in the query string, including quotes and angle brackets.
So, if you access location.href via JS, the payload in your example will be returned as
test%3C/option%3E%3Cimg%20src=x%20onerror=alert(1)/%3E
. This does not produce any HTML tags unless you URL-decode it first.
Note: As far as I know, all modern browsers now behave that way, but historically, some implementations have implicitly URL-decoded values for the location interface. In these browsers, your attack would have worked.
answered yesterday
ArminiusArminius
37.8k13123120
It doesn't work because the payload is URL-encoded.
If you navigate to
https://example.com/?foo=<>"
you will see the literal characters <>" in your URL bar, but the browser has actually requested
https://example.com/?foo=%3C%3E%22
. That is, your browser always URL-encodes some characters in the query string, including quotes and angle brackets.
So, if you access location.href via JS, the payload in your example will be returned as
test%3C/option%3E%3Cimg%20src=x%20onerror=alert(1)/%3E
. This does not produce any HTML tags unless you URL-decode it first.
Note: As far as I know, all modern browsers now behave that way, but historically, some implementations have implicitly URL-decoded values for the location interface. In these browsers, your attack would have worked.
answered yesterday
ArminiusArminius
37.8k13123120
edited yesterday
answered yesterday
ArminiusArminius
37.8k13123120
answered yesterday
ArminiusArminius
37.8k13123120
answered yesterday
ArminiusArminius
37.8k13123120
37.8k13123120
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
add a comment |
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
Oh I see... Ok ! Thank you so much ! So this webpage is not vulnerable anymore ?
– Neolex
yesterday
2
2
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
There may still be browsers that let you sneak literal quotes and angle brackets somewhere in the URL where they don't get URL-encoded. But I believe your example isn't vulnerable in modern Chrome and Firefox.
– Arminius
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
Ok ! Thanks a lot !
– Neolex
yesterday
add a comment |
Thanks for contributing an answer to Information Security Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsecurity.stackexchange.com%2fquestions%2f206018%2fwhy-isnt-this-xss-working%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
-xss
