Sielco PolyEco Digital FM Transmitter 2.0.6 – Authorization Bypass Factory Reset
## Exploit Title: Sielco PolyEco Digital FM Transmitter 2.0.6 - Authorization Bypass Factory Reset ## Exploit Author: LiquidWorm Vendor: Sielco S.r.l Product web page: https://www.sielco.org Affected version: PolyEco1000 CPU:2.0.6 FPGA:10.19 PolyEco1000 CPU:1.9.4 FPGA:10.19 PolyEco1000 CPU:1.9.3 FPGA:10.19 PolyEco500 CPU:1.7.0 FPGA:10.16 PolyEco300 CPU:2.0.2 FPGA:10.19 PolyEco300 CPU:2.0.0 FPGA:10.19 Summary: PolyEco is the innovative family of high-end digital FM transmitters of Sielco. They are especially suited as high performance power system exciters or compact low-mid power transmitters. The same cabinet may in fact be fitted with 50, 100, 300, 500, 1000W power stage (PolyEco50, 100, 300, 500, 1000). All features can be controlled via the large touch-screen display 4.3" or remotely. Many advanced features are inside by default in the basic version such as: stereo and RDS encoder, audio change-over, remote-control via LAN and SNMP, "FFT" spectral analysis of the audio sources, SFN synchronization and much more. Desc: Improper access control occurs when the application provides direct access to objects based on user-supplied input. As a result of this vulnerability attackers can bypass authorization and access resources behind protected pages. Tested on: lwIP/2.1.1 (http://savannah.nongnu.org/projects/lwip) Vulnerability discovered by Gjoko 'LiquidWorm' Krstic Macedonian Information Security Research and Development Laboratory Zero Science Lab - https://www.zeroscience.mk - @zeroscience Advisory ID: ZSL-2023-5768 Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2023-5768.php 26.01.2023 -- index.htm: ---------- 54: function dologin() { 55: var hash = hex_md5($('#password').val() + id); 56: $.get('/login.cgi', { 57: user: $('#user').val(), 58: password: hash, 59: id: id 60: }).done(function (data) { 61: var dati = $.parseXML(data); 62: id = $(dati).find('id').text(); 63: user = $(dati).find('u').text(); 64: if (id == 0) 65: window.location.href = 'https://www.exploit-db.com/index.htm'; 66: else { 67: scriviCookie('polyeco', id, 180); 68: if (user >= 3) 69: window.location.href = 'https://www.exploit-db.com/protect/factory.htm'; 70: else 71: window.location.href = 'https://www.exploit-db.com/protect/index.htm'; 72: } 73: }); 74: } The function 'dologin()' in index.htm is called when a user submits a login form. It starts by calculating a hash of the user-entered password and a variable 'id' using the hex_md5 function. Then it makes an HTTP GET request to the 'login.cgi' endpoint with the user's entered username, the calculated password hash and the 'id' variable as parameters. If the request is successful, the function parses the XML data returned from the server, extracting the values of the 'id' and 'u' elements. Then it checks the value of the 'id' variable, if it's equal to 0 then it redirects the user to '/index.htm', otherwise, it writes a cookie called 'polyeco' with the value of 'id' and expires after 180 days. After that it checks the value of the 'user' variable, if it's greater than or equal to 3, it redirects the user to '/protect/factory.htm', otherwise it redirects the user to '/protect/index.htm'. An attacker can exploit this by modifying the client-side JavaScript to always set the 'user' variable to a high value (4), or by tampering with the data sent to the server during the login process to change the value of the 'user' variable. It also works if the server's response variable 'user' is modified. |